The ACO have published their list of what you can and can't take into the circuit and car parks and campsites.
No surprises with some - cans but no bottles, no drones, guns, throwing stars (!) or fireworks anywhere, and surprisingly, no bicycles - anywhere - although scooters (non motorised) are allowed in car parks and campsites. And no dogs in the circuit (unless assistance dogs).
I suspect the bicycles prohibition will not be wholly enforced.....