I chipped a tooth, what are they going to do?

They'll probably make a tiny tooth-piece out of resin or the same enamel they make veneers out of, and replace the missing piece. Or, they'll cover the whole tooth with veneer. It probably hurts because it's a mouth trauma, which always seem to hurt more than anything. Your gum is probably bruised. Take some over the counter painkillers like tylenol or something. The dentist may give you something topical too. Sorry this happened to you...good luck!