Well done for installing Linux! Thats a big list you have there and without knowing what your hardware specs are or your budget, I’d suggest getting a hard-drive to replace the one thats failing. Maybe another one to back it up. If you don’t have a lot to back up then perhaps a usb stick will do that job for you.

Your list can be very expensive what with Ubiquiti and a NAS. Your router, whatever it is, will probably do for now and you can use up your motherboards spare SATA points for storage or even pop a harddrive into a usb hard drive enclose. Those are cheap. Life is easier if you have more than one computer to hand.

Definitely learn docker, find the code for Pi-hole and learn to set it up, thats no.6 done. Do the same for vaultwarden no.11 For convenience: All the basic stuff exists on DietPi so look that up, its a bit odd. Most of it will run on a Raspberry Pi 3.0 and up, possibly less. DietPi also runs as an operating system on PC architecture.

Debian (and most Linux Distros) will run as a server but you might find its a bit harder work to configure. You can run a VM within it.

If you intend to access your stuff from outside your router, you can run a proxy like Nginx or Caddy or Traefic, but you’ll need to register a domain. Just check with your ISP that they allow that. Alternatives are available.

Its easy’ish to just setup a VPN server using Wireguard and connect to that via a wireguard client from the outside. You could use Tailscale, Zerotier or Netbird (et al) which will give you more flexibility and security, ie for connection to your cameras, Game server, Nextcloud and Immich, and Home Assistant. This would also allow connections to vaultwarden. If you wanted you could build it yourself.

Anyway start small. Satisfy your immediate needs, make it work. Re-evaluate, can it be done better?, Next steps, implications of changes on performance, cost and future needs. Knowledge gaps?

You don’t have to decide now as there is loads of things to read and view, suck up the knowledge and enjoy.

This was too long, sorry