I have Newzik, and while the details are different from Forscore, I think there’s a lot of very similar functionality. I highly recommend looking into layers if you’re taking lots of notes, as this will help you keep all your notes associated with the piece and you don’t need to have extra pdfs. You can organize things however is most convenient — you could do a separate layer for each lesson, or you could have layers for fingering, phrasing, etc. whatever makes sense for you. But layers are very helpful, and you can instantly make them visible/invisible.
Newzik also has a built in metronome, which is very convenient—don’t need to have a separate app or device.
If you get into longer/more complicated pieces, you can duplicate pages so you don’t have to ‘go back’ for repeats, there’s the bookmark feature and lots of other things. But I think you will find the layers very helpful.