I bought the car seat before hand because they don’t let you leave the hospital without one, and I didn’t want to put my husband in the position of having to run out and get one on the spur of the moment.
As for not knowing the gender, just get a few gender-neutral outfits, they do exist. Also, all our baby gear is gender-neutral because we want to able to use the stuff for subsequent kids IY’H no matter what.