@RVER
Hmm. Well, I know what you're talking about, and I solved that a while back and no longer recall the details exactly. There are some things I haven't figured out how to do either so we're in the same boat. I did use it for 440 miles between Beatty, NV and So. Lake Tahoe and it did fairly well, except I haven't figured out how to get it to give up on a route that it likes and take a different one. Soon though.
Anyway, onto your issue...somehow, find your way to the 'Navigation Menu'. Tap 'Destination'. Then tap, 'History'. Then tap the little trash can to delete that address it's going to.
Alternately, you can tap 'Route Options' and then tap 'Cancel route'. That should do it. That's how I usually do it.
But in general, everything you need to do can be adjusted from that first 'Navigation Menu' page. Then the nuts and bolts of the device are on the bottom of that page. The Erlenmeyer flask icon and the crossed screwdriver and wrench icon let you set up things to your liking.
Find that menu, and you'll be an expert in no time.
I do like the large colorful screen and the way they present upcoming turns, show the road I'm on, label POIs etc. I still think it was worth the $50 I spent for it.