Waypoints do work, but they rely on everything else working well.
I suggest that you first make sure your copter flies well in VelocityRoam mode because it uses the same subsystems.
Before doing waypoint flight, you need to make sure that Home Location is set correctly, preferably close by, and that the Home altitude is correctly set. If you have never done it before, the best way is probably to have it set up to set Home Location each time you start up and get a good GPS lock. I prefer to wait longer to get a better lock and make it a permanent setting.
For first waypoint flight, make your waypoints close to you (less than 100m or so) and use just 4 waypoints or so.
(from memory) to do waypoint flight you click a point on the GCS map. Then right click and select "add waypoint". Repeat. When finished, right click and select "waypoint editor".
In waypoint editor you must change two things about each waypoint:
- set the speed. make it slow for first tests. 3 is probably a good number
- set the altitude. the default of 0 is ground level.
altitude is the least accurate part of GPS, so make it at least 4 meters.
Upload the flight plan using a button at the top of the WP editor. Note that it is not stored permanently so you must upload a plan each time you power on.
Take off in Attitude mode (you need attitude mode available at least as the quickest way to get stopped and level).
Keep your finger on the switch when you switch to PathPlanner mode. And plan on switching to Attitude mode. If it all works OK, you can abort that plan and let it fly.