Question about Garmin Edge 830

You can plan routes on the device. It's not exactly a blessing in terms of operation. But it's simple point-to-point without any big wishes on the road. That works quite well.
All GPX files can be loaded onto the device. Even without Basecamp. I always plan routes in Basecamp or Trailforks and then load them as GPX on the device or call them up via the integrated Trailforks app.

I work with Komoot. For me, it's the best tour planning software. On the Garmin device you can then select the tours directly in the Komoot app and drive/navigate them.