In line with other commenter’s posts about security, if you’re new then don’t expose anything to the internet. Tailscale is great way to access your data remotely instead and doesn’t require opening yourself up to the internet in mass.

As for hardware, budget will rule over all. If you’re looking for a quick and dirty backup solution, then a raspberry pi with a drive attached and running syncthing will be perfect for you (and easy to setup). Again all on your tailnet/tailscale.

If you have more budget, then your options explode. You can use a whole range of hardware, OSes and software. Regardless, start with one service you want to run and go from there. Sounds like that’s media and pictures for you (as it was for most of us here).