How to use GPS for hikes

Hello everyone,
I am a total noob here. Sorry if this is the wrong spot or repetitive info. I have recently gotten a garmin fenix 5x. I am loving it. I am a hiker and crossfitter and spartan racer. I have been using the fitness tracking quite well, but I am needing to learn how to use it for hiking. Do I have to download maps and stuff for it or is some stuff saved?

The reason I ask is because in August I am doing a Rim 2 Rim 2 Rim hike of the grand canyon. I would love to have the trail on my watch so I can see how far I am to the Phantom Ranch and be able to use it to figure out how far I have gone and how far I still have to go to the ranch and from each rim so I can space out water and snacks. I also would love or apreciate any tips for using the watch in this manner. I have googled alot and seen videos of having to use garmin connect to get stuff on the watch, but was not sure if I needed too. There is so much info out there its a little overwhelming so I figured I would look to the community for direction. Thanks guys!