There was a steep learning curve (for me) to learn BaseCamp basics.
BaseCamp has a nice "Optimize Route" feature that I like.
Yes, once you have a route, you can export it to the Garmin GPS unit.
However, I use Google Maps (MyMaps) to find places, save them on the map and then export them to a KML/KMZ file - which can be imported to BaseCamp, then optimized, then downloaded to the Garmin.
BaseCamp forum for Win/Mac users:
https://forums.garmin.com/forum/mac-windows-software/windows-software/basecamp-aa?179-BaseCamp=