If I want to travel to a different state, can I do it without an id? ?

As a passenger in someone's car or private plane, yes.  Otherwise, you are going to need some kind of ID to drive, ride a bus, or take a airline flight.  Interstate buses and trains require an ID to purchase a ticket, and of course you need one to get on a commercial plane.

not likely as if you get stopped or robbed, you will need some form of id so they can identify you

Yes comrade.   Just quarantine for 14 days when you get there.  

In the U.S.: yes.

However: if you are an adult

or a minor not escorted by an adult

an I.D. might come in handy if you have any interaction with any law officer for any reason.

Yeah. Just don’t drive a motor vehicle to get there. Whatever transportation you use, pay with cash.