To start your legal operation in any state, you should get everything ready in advance. This means that you can’t sell, serve or start operating before getting licensed. Otherwise you may get penalized and fined as you violate the state regulations. Worst case scenario is you might not be able to operate at all.
As soon as you obtain all the required licenses, you can open your business to your customers without any issues. However, don’t forget about making their copies and keep track of the renewal dates.