Hey Natalie. How exciting. I know how you feel.
What do I need? a lot of patience
What should I buy before he gets here? Pee pads, somewhere (a bed? pillow?) for him to sleep.
What should I do when he gets here? Let him sniff around and show him where the potty is first and foremost.
Should I potty train him RIGHT AWAY? I would say DEFINITELY
Good job making the vet appointment - very important.
Congratulations on your new baby. Can't wait to see more pictures of him.