The fine for expired registration on your vehicle can vary from State to State but in most places the fine for expired registration is $75.00 and if you don't have insurance you can get another fine of around $500.00 plus maybe even get your vehicle towed and impounded.
Most times though if you have insurance on the vehicle and a license and it's your first offense with expired registration you'll get a fine and maybe be able to drive the vehicle back home.