How to prepare for a weekend trip?

This is a stupid question, but how do you prepare for a weekend trip with two kids? Friday myself, my boyfriend and our two kids (6 and 3) as well as my boyfriend’s best friend leave to go to Gettysburg until Sunday. The only trips we’ve taken have been to my boyfriend’s Aunt’s house in the Poconos so we didn’t really have to bring much. Also it’s only about an hour trip, it is going to take around 3 hours to get to Gettysburg (well longer with break room breaks and such.)

Any tips/suggestions as to what to pack and how to make the trip there easier for the kids would be appreciated :)