First of all, check the final instructions documents to find out when and where access into the circuit is permitted. Each circuit will have a different access time and it will also depend on whether or not you will be testing on the Friday before the meeting.
You will also find within the final instructions information and guidelines on how to use the pit and paddock areas, such as where to park private cars, engine/ noise pollution, general paddock and pit lane rules, support vehicles and use of paddock vehicles and tail lifts. Please make sure that you read, remember and adhere to these guidelines, otherwise you may find yourself reported to the clerk of the course for contravening any of them.
Within your final instructions document, you will also find a paddock plan which details which part of the venue your championship will be setting up. If your championship is fortunate enough to have been allocated use of the circuit garages, there will also be an additional garage plan either within the same document, or sent separately by your championship co-ordinator, letting you know exactly which garage you have been allocated and where to set up.
It is also useful to let your championship co-ordinator know what kind of vehicle you will be turning up in if transporting your race car yourself or arriving with a team, be it either a conventional or box trailer, a van or an articulated lorry and transporter. Providing this information ahead of time will make it easier for the organizers and co-ordinators to plan out who goes where for the weekend.