how to create new course preferably on a laptop, then send it to the Edge

A lot of questions, best answers might be if you have a look at ridewithgps.com (RWGPS) which is one of the (maybe be best) computer based course planning sites, there are others including Garmins own connect.Garmin.com (IMO not very friendly and far from the best).

You can do everything you describe above with a free RWGPS account although some useful, but not essential, features are available to paid account members. The RWGPS help is fairly good and covers your questions but if you have specific issues / questions this forum is full of RWGPS “expert” users. You can build a course without specific turns (called cues) and then let the 1040 do on device route creation (with “Turn Guidance” ON) or you can let RWGPS create cues for each turn and these become Course Points (sort of like Waypoints) in the exported Course file which you load onto the 1040 (via device Newfiles directory) and you use it with on device Turn Guidance OFF. There are a lot of details but you will get the hang of it quickly and become one of the “experts”.

When you plan a course make sure you select the OSM base map option as this is the same source as the Garmin on device maps and will minimise issues related to differences in the maps.

Good planning and good luck.

ps If you mastered Basecamp then RWGPS will be a piece of cake

Did you try using Garmin Connect web? Just create a course there and it will sync with your Edge 1040. For it to work it requires you to either have your device setup via the Garmin Connect mobile app or via Garmin Express on a PC. See instructions on Edge 1040 Owners Manual - Following a Course From Garmin Connect (it helps to RTFM )

Besides Garmin Connect there are many third party alternatives that allow you to create routes and have them wirelessly synced to your Edge. So no need for messing around with cables, connecting to PCs and exchanging GPX files.

Some examples of these third party sites are Strava, Komoot, RideWithGPS. All three allow you to connect to your Garmin Connect account for the wireless sync to work. Some of these third party services require you to have a subscription with them for these features to work so be sure to check what is supported in the free version.

I would not recommend using Basecamp with the Edge, since that software is not officially supported and updates anymore. Also Basecamp can only handle Tracks and Routes while Garmin fitness devices like the Edge work with Courses which work much better for navigation purposes with these devices and does not require the map where you planned on to be exactly the same as the map on the Edge.

And for your last question, navigating back to start, the Edge provides a very simple feature for that: Edge 1040 Owners Manual - Navigating Back to Start (garmin.com)

JungleJim said:

Also Basecamp can only handle Tracks and Routes while Garmin fitness devices like the Edge work with Courses which work much better for navigation purposes with these devices and does not require the map where you planned on to be exactly the same as the map on the Edge.

(This isn’t quite correct.)

Courses are really just tracks.

They can contain “course points”, which are embedded turn instructions, but they don’t need to (“course points” are optional).

BaseCamp doesn’t deal with “course points”. So, you’d have to use something else if you also want to use “course points”.

Garmin Connect and RideWithGPS (RWGPS) will add course points to the course/track. Both let you add custom ones for things like food stops but you have to have a paid subscription to do this in RWGPS.

For devices like the 1040, Garmin Connect only includes the custom points (not the ones for the turns). RWGPS includes all of them.

Most people are probably using “turn guidance” and not “course points”.

”Turn guidance” gives you turn prompt that are more clear than “course points”. Turn guidance is more like what you see with a navigation app on your phone.

The device itself produces the “turn guidance” prompts by following the tracking and seeing what roads/paths on the installed map the track appears to follow.

Note that “course points” and “turn guidance” are separate. The are two different ways to provide turn instructions. You can use one or the other or both at the same time (but using both can be a bit confusing if you aren’t clear about how they work).  One difference is that “course points” don’t use the map on the device while “turn guidance “ does.

Ideally, you use the same map to create the track as installed on the device. The maps on the recent Edges are all based on Openstreetmap (so use a map based on Openstreetmap to create the track). All the online route planners let you choose one or more Openstreetmap maps. The Edges generally handle map differences if they aren’t too drastic. But there isn’t really any reason to use a different map.

A “route” file often refers to a “waypoint” file, which just includes the places you “must” visit (and no information about how to move between these places). TgecEdges cannot use these kinds of files.

A “track” file contains many points. Enough to accurately trace the turns and curves of the path you want to follow.

BaseCamp has no problems creating “track” files. BaseCamp is designed to use the maps on your device when you plug your device into your computer. It’s also not that hard to use maps on your computer (so you don’t need your device to be plugged in). You’d just get Openstreetmap from some other source (there are free sources for these maps). While Garmin isn’t actively working on BaseCamp, it’s still supported (minimally) and will work for many years regardless.

Still, like others have mentioned, I’d also recommend using one of the online route planners. You’ll likely find them much easier to use.

Open your laptop and visit https://connect.garmin.com

Login with your credentials

Go to training and courses

Now create a course

Save and send to device.

It seems like the best is to go with RWGPS. I hope it is not too expensive. I have access to some level of RWGPS from my bike club but it I guess I can't edit/create with that access.

Yes good addition, I didn't mention course points to keep things simple but they are indeed supported in Courses in FIT file format (and technically in TCX files as well).

Still in my experience I would always recommend to use Courses with the Edge since it provides a better navigation experience and is easier to use with all the wireless syncing options available.

Courses (in FIT file format) have much fewer limits on number waypoints or trackpoints and often the re-route experience is better when you miss a turn or deviate from your originally plotted path.

JungleJim said:

Still in my experience I would always recommend to use Courses with the Edge since it provides a better navigation experience and is easier to use with all the wireless syncing options available.

Again, courses are just tracks.

"Courses" is jut Garmin's odd name for tracks (no one else uses it).

The files that Garmin Connect produces aren't any different than the files other services (like RWGPS) produces.

They do not "provides a better navigation experience". They work the same because they are the same.

Garmin Connect might be a convenient place to plan routes but that's a separate issue.

LINYBob said:

It seems like the best is to go with RWGPS. I hope it is not too expensive. I have access to some level of RWGPS from my bike club but it I guess I can't edit/create with that access.

The free subscription will provide most of what you need. 

Garmin Connect is a reasonable choice too. It's not really harder to use than RWGPS but RWGPS gives you some extra tools (that are very nice).

Any planner you choose to use will produce files that will work equally well.

Getting a bit off topic and I think we're in getting a semantic discussion here, so let's agree to disagree. If you want to continue the discussion that's ok, just send me a private message 

No it's not a "sematic discussion". Nor, is it "off topic".

There is no magic pixie dust in the files that Garmin produces.

They don't "provides a better navigation experience".