Stay away from Plex, if you like to go with Free and Open source.
I’ll start with Jellyfin, and Arr family (sonarr,radarr,prowlarr or Jackett), Vaultwarden and immich
Edit: Learn to spin up docker instances first, as above services would be easier to manage in docker containers and for back ups I prefer Duplicati. And if you run it 24x7 add AdguardHome or PiHole to the mix
Edit1: if you are extremely new to docker instances and find it hard to learn, just spin up CasaOS and you’ll be good to go as it makes spinning up docker containers so easy.