Bleachbit could definitely be it, but without knowing if it was right after running it your problems happened it’s hard fix. Without knowing what distro or DE your running makes it’s harder.
Since you’re just starting out I’d suggest flashing a new distro and don’t worry about running the same utilities as you did on window. Linux works a lot differently then it.
Search the forum for one of the updated distros to run if you were using the stock clockworkpi image. I would suggest Debian Bookworm and install something like Pi-Apps for a software store to start.