Shower curtain! Nothing worse than moving in all the boxes, unpacking, going to wash up at the end of the day and discovering you can’t take a shower without hosing down the washroom!
You’ll also want to move in with toilet paper.
Dishsoap and sponges/cloths whatever to clean dishes with, and paper towels are also very useful, since theres a good chance youll be packing your glassware in newspaper and no one wants to drink from inky glasses. On the move-in day, as soon as you have access to the apartment, send someone out for basic groceries - milk, bread, eggs, breakfast food, supper for a day or two, etc.
You might want to have a mop/broom/vacuum right away, for who knows what the previous tenants left behind! A garbage can or plastic garbage bags are probably a good idea too. If you don’t have curtains, have masking/painters tape and big garbage bags to use in a pinch - our apartment has a streetlight just outside the bedroom window, and the first night was SO BRIGHT!
Confirm that your electricity and heat and phone will be activated on time - you don’t want to spend your first night(s) in the cold and dark and being unable to call for help! Also have a toolbox, just the basics should be good, in case there are any minor repairs (like tightening a shelf screw or something). Make sure all keys given to you work, and that the locks are functional, or get them fixed ASAP if there;s a problem.
And just in general, look up your local housing regulations and KNOW YOUR RIGHTS. Some repairs are your responsibility, others are your landlord’s, etc. Know when you can and cannot withhold rent, if at all. Just good advice for anyone renting, in any city.
Good luck and have fun! I love living with my SO, but we made mistakes in the beginning which we really should have avoided!