First ever MAC product? Studio Fix Powder in N3. I needed foundation for a formal and Mom had heard from a coworker that MAC made foundations paler than what could be bought in a drugstore, so she took me there and got me matched. At that point I had a slight tan, so actually it was a perfect match.
First MAC I bought? Prunella Eye Kohl and Plushlash mascara. Oh, and I believe that's when I got my Select Moisturecover. (The batch code on the label matches up with when I would have been in that MAC, so I am pretty certain that's when I got it.) I'd gone in to get rematched, because I was tired of the finish of Studio Fix Powder, but wasn't sure if I liked how the foundations tried on me looked. But the MUA was nice enough to also offer eyeshadow suggestions and do my eyes for me, and I would have felt bad not purchasing anything. So I got the concealer, eyeliner and mascara she used. I now wish I had gotten the eyeshadows as well (such gorgeous purples!) and not bothered to purchase the SFF, because while at the time of being matched it WAS perfect, about six months later I did not have the tan I'd had when matched, and haven't tanned since. (Irony: I got matched in the middle of winter deliberately because I was certain I would be at my palest then. And it did match in natural light!)