With the price of a lot of the SBC’s you will probably be better of going for something like as dell 3050 with a gen7 or above in it.
I picked up a gen7 dell 3050 with 4Gb and a 500Gb disk for £50. Threw in a 1tb nvme a 120gb ssd and a spare 500GB ssd I had. Installed Debian with KDE , then i set up the drive shares via sftp, installed Docker and setup the various docker containers such as freshrss, kodi, Firefox ,Pi-Hole etc.
What ever route you go have fun starting you journey in the world of self hosting.
May I suggest that you visit https://homenetworkguy.com/. Will give you plenty of information on what you are looking to do.
It helped me do the same.