They're very determined idiots so they're going to head inside. Since it's getting close to camp time, they'll go to the garage like building to make sure it's clear, to explore it and check for supplies, but also to sleep in shifts.

In the 'morning' they'll split up to look for supplies, equipment, and clues without traveling too far from each other. Bruce specifically will be looking for records, papers, photographs- anything that might contextualize this place they've discovered focusing mostly on the garage area and the boat. Vanitas's unversed will be able cover more ground for them- rooting through cars while Vanitas himself will be doing a great impression of that kid sent to summer camp who doesn't want to be there. So long as there aren't any weird doors to open or mysterious buttons to push he'll probably keep his shit-stirring to a blessed minimum. Jason, as their resident superman will definitely get asked to fly up and check out that crane. Sorry dude.