what to get

Hey ladies I was wondering what I really need to get for my baby? I'll be having a baby shower next month, but I would like to get a few things myself:) so far I got a crib, getting a bassinet, car seat, swing. I still need to get a mattress for the crib but was wondering if all mattresses are one size? a stroller too. but idk what important items I should be getting that the baby needs most of all.