Hi all, this is my first post here

I currently have a 12 gal Fluval Edge and i'm interested in converting it into saltwater. I've been looking up how to convert the tank, and I have a couple questions about it before I go ahead with converting it...
1) Do I
need to buy a new light? I do want some corals, but i'm not too bothered if keeping the original lighting limits my coral selection too much.
2) Do I need a protein skimmer for such a small tank? I've seen some people say that you do need a skimmer, while others say that it isn't completely necessary.
Thanks in advance!