Always
the puss first since I've never met a broad that couldn't cum that way.
After that she will do anything you want. She may or may not come from penetration so there's no point in relying on that...especially with someone you just met.
Eat the cooch, she finishes, you bust a quick nut just to get that first time with a new girl feeling out the way... then you warm up for round two and pound away. If a girl is really fine and she got a good box, you will finish fast the first time unless your nerve endings are dead (circumcised brehs)