If I just go for a stroll with my dog on no preset route, how do I track my walk, simplest way to do it. Fenix 5 plus

Simply start a Walk or Hike activity and off you go. 

Sorry I wasn't very clear, I'm looking for an easy way to have my walk showing on the map and a redline showing my route. I've done it once but lately don't seem able to do it again.

Should add I want to see my route showing on watch face, many thanks

I just tested it myself. Just starting a walk and switching to the map the red line is drawn as I walk with no preplanned route. This was just walking around my back garden. Make sure the zoom scale is appropriate to show something. 

Actually, this is with my 6X. I assume the 5+ can do the same. 

Similar but yours is not showing a street type map showing local area. 

That's because it is zoomed into my back garden. You can see a street in the top left edge of the display. If I zoomed out or panned the map you would see streets shown. 

Ok thanks, how do you get to that if I press walk, do I then go to options or what? Your help is much appreciated. 

Within the Walk app I have two screens configured. One is some data fields. The other is the map. Simply start the Walk and scroll to the map screen. The red track should appear automatically as you move. 

Brilliant, thanks, just what I needed to know, cheers