[sn0n]

Have you looked at nextcloud? Or maybe even syncthing?

I've been having a lot of luck organizing my life with nextcloud this last few months. It does take a little bit of setup, but it has notes, files, and lots more.

Another option is an app like notable (markdown notes) and something to sync across devices with. I hear a lot of people use syncthing, I haven't personally, I have a private git server that I've used in the past, but I've since migrated everything to a private nextcloud server that's only accessable by wireguard when remote or wifi when at home.