You will be getting a lot of responses and each person has their favorite:
For displaying a GPX file on a moving map, I use an old phone (because I seem to always have an old iPhone that someone in my family deems obsolete) and the app "OSMAND"
Phones will still work as a GPS without service, and OSMAND (iphone or android) has the maps stored offline. You will need to have downloaded the state(s) you want before you leave your home wireless.
OSMAND can also record your route. *DOWNSIDE* OSMAND is running on a phone so it is not very glove friendly. I don't want my cell phone mounted on my handlebars as I prefer to keep my phone on my body
just in case I am forcibly separated from my bike and need to call for help.
For reviewing a GPX file on a PC there are a lot of choices: Google Earth, GPXSee are Free Garmin's "BaseCamp" will work, but it will only have detailed maps if you have a Garmin GPS (or at least that was how it was when I last used it).
Even though I seem to get plenty of suggestions of where to go...
I still like to figure out my routes. For that I have found "Furkot" very nice, and you can share routes with others or search for scenic route suggestions that others have uploaded.
Live Updates of where you are: So to have live updates you need a phone that has a data plan, and for that I use "greenalp"
https://www.greenalp.com/RealTimeTracker/ You can use greenalp to record your track but they have a monthly fee if you want to keep more than just the recent track points.