Thanks for the link. It's something I will keep in mind.

In the meantime someone on a different site suggested a phone app called Trimble Outdoors Navigator. I downloaded the free version and my initial impression is it will do what I need. It's actually pretty neat. I'm still learning but I did save a GPX file, opened it in GoogleEarth, and it showed a satellite map with my route plotted on it, as well as the waypoints I marked along the walk. If I get competent I may have to purchase the full version.

I actually thought of this as a fantasy job several years ago. Hike trails, or non-trails, and plot them on a map for towns and counties. Mainly focus on tourist areas wanting some walking trails. Now that I'm learning how to do it, I wonder if I could actually get anyone to pay me, at least expenses.