Myles
Fuel is available down the road, best to pop out at lunchtime and top up. A torque wrench for checking wheel nuts, tyre pressure gauge would help. I usually take spare throttle cable, exhaust bobbin, engine oil to top up if needed, some masking tape in case anything needs temporary fixing onto the car. You can take the kitchen sink but you can guarantee whatever may fail you won’t have it, although someone else might.
As for booking it in for a service, hopefully you’ve done that before but it’s always worth getting the car checked over after by someone who knows what they are doing after some hard track miles. Caterhams are built for the circuit. Tyres wear a lot less than those heavy tin tops.
Enjoy it.
Nick