I think what you may want is a "Track", not a "Route".

There is software with tools to draw a track on a map and load it into your GPS. You can make a different track for each day of your planned hike and select the one you want to follow. (I think someone here recently posted a link to a website that has tools for this too, you might search for that)

You can save "Tracks" when using your GPS. Clear your Track Log at the trail head, waypoint your car, and start hiking. Save the Track when you reach your destination. Select it for the hike back. This is especially useful when bushwhacking off trail.

The best thing to do is to carry your "Quick Start Guide" with you and play with all the features until you remember how to use them. I carried mine for about a year.