Am I stuck with what I got?

NUC5i3RYH Intel (R) Core(TM) i3-5010U CPU @ 2.10Ghz running Win 11 21H2.

I have had it for either 3 or 5 years, I honestly can't remember.

I mainly use it for a Plex Media Server.

It stopped getting updates a while ago.

Unsure if I can increase the storage space myself or update the software.