backup apps

I started collecting a lot of notes on my phone (oneplus 6t) since it was so accessible. Because I didn't want to lose these notes, I wanted to back them up but couldn't figure out how to. Ideally I'd back-up the notes to my harddrive on my computer, but when I plug my phone into my computer...

Hi, Looking for an app that automatically backs up apps every time before I update them to allow downgrades to earlier versions in case updated app is not good. Preferably should auto-backup to cloud services like Google Drive, OneDrive, Dropbox etc. Thanks