To be honest, I don't necessarily recommend that anyone host their own email. For a less monopolistic option, try something like Proton Mail first.
If you really want a new long term hobby, I highly recommend the guide at https://workaround.org/. I've built servers from the ground up with it twice, and I still refer to it first when I have questions. It uses postfix and dovecot, and targets Debian as its preferred OS. It has given me lots of education into how email works and quite a few years of stable personal email use.