I think the paperwork when you enter most countries will ask for your accommodation in the country, but it's often an awkward thing when you plan to move accommodations a ton and the paperwork only asks for one address. If you plan to book a hostel then make sure you have proof of that booking. I usually provide contact info for my first accommodation on the paperwork, but given the US's current uh situation hopefully you'll get some comments in here from recent non-US-citizens who visited the US recently and can provide perspective. Sorry for the extra stressful bullshit you've gotta worry about visiting the states these days