Hello. I've never owned a Mac and am wondering what I will need to set up a server. My PC That I use as a media server had an unfortunate accident and I am not looking to replace it. All I will be using it for is plex, picture storage, and occasionally accessing files when I'm away.
Are you saying you want to get a Mac to use as a server, or you want to set up a server that you'll access from the Mac?
Assuming the former:
First, you
don't need to buy the "Mac OS server" add-on that you'll find in the App Store.
Plex: I believe Plex server runs fine on a Mac, nothing extra needed.
Picture storage (on your local network): Doesn't Plex do that? If not, just enable sharing in system preferences (On older versions of MacOS there is a separate checkbox for "Windows file sharing" if you connect from non-Macs) then "Get Info" on your pictures folder and make it a shared folder.
Accessing files remotely: for most people, the easiest/safest thing is to use "cloud storage" such as DropBox, Google Drive or Microsoft Drive to store files you want to access remotely - there's a list of reasons why home network connections aren't great for running remotely accessible servers (dynamic IP addresses, slow upload speed, ISP terms & conditions, accidentally letting hackers own your home network...). Other solutions are possible, but beyond the scope of a short post!
Re what @
crewkid89 said - Yes a NAS might be a better solution, but the wrinkle is whether or not they are suitable for running Plex, and whether you need transcoding support in Plex. You'll need to read this:
https://support.plex.tv/hc/en-us/articles/201373793-Is-Plex-Media-Server-on-a-NAS-Right-for-Me-
Otherwise, Mac-wise, the best tool for the job would be a second-hand/refurb Mac Mini.