Hardware recommendations

Hello everyone. Currently I have a Minecraft server and a Jellyfin server running on an old Windows 10 gaming PC, but it's too hot and it makes working in my office (where my UDM SE and switch are in). Both applications are running on a 1TB platter drive. I would like to setup something that is at least cooler and less power hungry to run, as well as give it redundant storage as I would also like to throw NextCloud, and a personal web server into that. What hardware recommendations would you all recommend.

As a bonus question, does anyone have any resources to learn how I could securely setup my network in order to be able to access my personal server from the web without a VPN (my kids would like to invite their friends to the Minecraft server :P)