I've been given an offer should I take a co-op or contract?

I think you should find out if you have an offer or not. Whatever they said is meaningless unless you have recieved a written and dated contract/offer. Get something in writing spelling out all the details first (including pay). If they give you grief because you asked for it in writing, chances are you probably don’t want to work with them anyways - its a sign of not-so-professional or ethical practices.