Diaper bag essentials

I’m due June 26th, which where I currently live means it’s going to easily be in the 90s and very humid, so keep that in mind please! I already have a diaper bag, it’s an itzy ritzy boss backpack diaper bag (that’s a mouthful to say!). It has a TON of pockets and storage spaces but I have no idea what to put it in besides a change of clothes, diapers, wipes, a bottle and formula. What would you suggest to keep for a newborn and yourself in a diaper bag? Also we’re going on a 5 day trip August 1st, we’ll only be about 4 hours away from home, that’s about half a state south. Any tips or recommendations of things to bring? Thanks!!