Burnley Shrimps I will have a stab at answering your question but it's years since I have been.
I believe there are three entrances to the ciruit and they all have car parks near by. I think there may be even some parking inside the circuit but not sure if this is for Disabled/VIP people only.
I found this website very helpful for info
http://www.driving-days.co.uk/oulton-park-circuit.phpWhen we used to go we nearly always went to Knickerbrook you get to see a lot of the track from there and the odd smash up at the chicane as they all try and fit through it.
Lodge Corner is also decent as you sometimes see them trying to outbrake each other and overtake just before the start finish straight and if your lucky one will get shunted off into the gravel trap infron of you.
There used to be designated times when you go into the paddocks and have a look round. back in the day the touring car drivers used to have a designated hour where you could walk down the pit lane and there was an autograph session where they all sat outside the garages giving away posters etc. I think this will probably be an hour or so before racing starts for a guess. Regarding the rest of the paddock which is where Costal will be I think you might be able to walk round here at anytime but I am not 100% sure.
It's deff worth a walk round and getting there early as you should get loads of free goodies for the kids I still have all mine stored away somewhere from all those years ago.
I always remember when Matt Neil was sponsored by Max Power as an Independant and the Max Power models used to stand outside his garage and their clothes were painted on

far to much for a young 14/15 year old to take in.
Hopefully 4G63 will eb able to fill in any gaps I have missed.