Lemmy Support

You primarily need Docker, specifically (unless you want to set it all up by hand) Docker Compose. All installation options for Lemmy utilize Docker to host the components (db, API, UI, etc.). Depending if you go the Ansible or Docker/manual route you will need Nginx as well.

You will need disk space to store content (including pictures). The CPU/RAM needs are super low unless you have a lot of people on your instance.

You will need a domain for federation to work (like my instance is at lemmy.wizjenkins.com).

Lastly you will need an SSL certificate but Lemmy can generate this for you assuming you have your domain pointed to your server before you start everything up.

I'm not familiar with QNAP but generally NAS servers don't support Docker Compose so you might be better off with a raspberry pi or VM or something.

If you're hosting QNAP at home, you'll need to setup the port forwards to allow outside access and point your domain to it. That might not be allowed by your ISP.

Lemmy is lite on resource usage. For space, it really depends on how much content you sync in, or directly upload. For reference, my own Lemmy instance is using 7.4GB of space after being active for two months.

You need a domain as well. Not much storage space is needed, 50gb is plenty.