First Road Trip! HELP!

FTM here! We are traveling about 9 hours to visit family in Ohio in a few weeks and am asking for travel/packing/feeding/maintaining a schedule tips for an extended weekend. My husband is so excited for "vacation", but I'm so stressed out! We've not spent the night away from home since we had our LO, and we're in a pretty good place now as far as our schedule. I'm just scared it's going to be a hellish four days. HELP! What are things I should pack that aren't obvious (clothes, diapers, toys)?