I can't imagine it would be any different between tracks but the general idea is to find your way to the pit area. You can park your car/trailer there. I like to park close to my bike.
As far as the trailer goes, if you have it, use it. Things aren't always rosy at the track and crashes happen. It would be easier to get yourself home when or if you crash.
As already mentioned, people at the track are usually very friendly. So don't hesitate to ask questions. There's always someone willing to lend a hand.
Here's a quick list of the things I take to the track:
1. Gear - suit, boots, gloves, helmet and under gear to keep me cool.
2. Gasoline - Usually two 20L cans but realistically, I only use one.
3. Generator + warmers
4. Basic tool kit
5. I pack my lunch, too much effort to grill something trackside
6. Cooler full of snacks, water, gatorade. I usually grab a 12 pack of water, 6 pack of gatorade and some red bull to get the adrenaline going.
7. Lawn chairs to relax between sessions
Most importantly, it's important that you go in with a positive attitude. Don't push yourself too hard, spend some time learning the lines and don't worry about going fast right away. Be smooth and speed will come.
Here's a picture of the pit area at the track i frequent, you can see some cars behind the wall, that's where I usually park: