Iris PC-21 setting up and flying a route

I decided to stop just slamming my PC-21 around at treetop / rooftop level and actually try some cross country flying. VOR navigation is fine but I’m darned if I can make sense of programming the FMC and how this turns into the waypoints shown on the left MFD.

I can sort of get a route into the FMC (but I haven’t worked out how to delete waypoints / procedures I’ve entered by mistake) and somehow this turns into waypoints, but then I can change the route - I think - and the waypoints don’t change.

Has anyone done a good guide on this ?

Cheers