If you haven't played the Strawberry Jam mod yet, it's very good, I recommend it a lot.
It's split into 5 sections, and roughly, Beginner lobby = as hard as A-sides and a few B-sides, Intermediate lobby = as hard as Farewell, and then it scales up from there. It's not expected that you finish the whole thing but even Beginner + Intermediate was a lot of content for me.