Hi welcome to yt and congrats on getting your first baby!
Well, some of the things that I picked up before I got mine were..............a nice soft little bed, a crate for him to sleep in at night, food, treats for puppies, if you are paper training him then you will need the pee pads......ummm, food and water dish, a couple of toys, dog brush, doggy shampoo. Just try and be aware of things in your apartment, like wires that might get chewed and cause shock, toilet seats being up, you know, just look around and make sure there is nothing that the pup can get into and get hurt on. Thats all I can think of right now but good luck and let me know how it goes.