I'd recommend using a test domain first
Having mail thrown away by accident is really annoying, especially when you only have yourself to blame. So if you are new to this, get yourself a domain to play with, and set everything up the way it should be. And test it properly. Domain prices vary a lot between the TLD's, but the .info domains appear to be cheap at the moment (29 kroner = ~3£ for a year at my local dns shop).
Having done this for 20+ years, my experience is that you shouldn't try this on a home connection. Too much hassle with ISP filtering ports, home DSL IP's being blacklisted etc. etc. And if you end up providing mail service to friends&family (and believe me, it will happen ...) then your home server suddenly needs to be up and running 24/7 - including power and Internet connection.
Much easier with a VPS somehwere, and it is cheaper on the power bill.
My own setup is based on https://workaround.org/ispmail/ - is uses Postfix and Dovecot on Linux. Sendmail? No way I'm gonna do another sendmail.cf voodoo dance again. QMail? Been there, done that - for 10+ years, actually, but it is definitely showing its age now, getting it to do spam filtering and avoiding backscatter mails was just too big a hassle.