Unless you decide to operate a push cart and have it stored close to your regular location, you will likely need a vehicle with a trailer hitch so as to tow your cart. You will thus be able to easily move it to your regular vending location and any other special events locations, and then return it at days end to store it in a safe place. The trailer hitch ball should match exactly the size of the trailer hitch on your hot dog cart. The towing vehicle should have an electrical adaptor so thay it operates the brake and signal lights on the trailer.
You may also need a regular convenient parking spot for that vehicle. Remember to keep all of the parking receipts for tax time. Those daily expenses will really add up to a significant deduction at year end.