No Build, reconditioned interior

I have an opportunity to buy a vehicle with a brand new exterior paint, wheels, rims and a strong motor. The difficulty is the interior has been gutted and reconditioned. It is completely open.

How can I use it this summer? Is there a way to anchor the few items I would want to take along: cot, cooler, kitchen? I was hoping not to make permanent changes.

I also have two dogs so they also need to be secured.

Thanks