If you are new to Fdroid or are looking for the best app recommendations, this is the best overview list of available Fdroid apps that I've found(made by justarandom).
The list is huge and can be daunting.
My quick recs and my most used apps are:
Jerboa, Simple dialer, QKSMS, Fennec Browser, NewPipe, QuickWeather, OSMAnd, Material Files, Simple Gallery, Vanilla Music, VLC, Alarm Klock and XMouse. Games: lichess, gurgle and sgt-puzzles