Yeah, a pi could probably do that, I know everything except the fediverse instance will work, and the fediverse instance may, I’ve just never tried it, so I don’t know!
One suggestion I’d make is this: A lot of tutorials these days will have you set things up in Docker. Docker is a great tool, and at some point in your journey you should learn how to use it, but it does sort of abstract away a lot of the services you’re running.