What comes first a bibliography or reference list?

Probably the reference list--so that you can look up what you need to. However, to save time, look up the style that the bibliography needs to be and do your reference list in that style. Then, at the end, you will certainly have all the information you need to do it correctly as well as having it done! Just make sure that you don't have items in your bibliography that you don't cite in your paper.