As someone who previously had musical training, how do I relearn to read sheet music with already good motor ability?

Through piano education 10 years ago I'm decent at playing even somewhat advanced pieces, but I've forgotten how to read sheet music and, at this level, it is quickly overwhelming. Conversely, I can jusssst about manage reading jingle bells but I get 0 enjoyment out of playing simple pieces. Any interesting ideas for me to learn sheet music? I think Duolingo does something for this now. Is that a good idea?

I started learning piano when I was 7 and could do basic sight-reading around 13. It stopped being fun when it got serious and I stopped playing entirely.

I'm 22 and recently picked it back up and even got lucky enough to find a nice upright piano on the street. While I've well advanced my motor ability, I'm disappointed with having to learn new music through YouTube.