If you are going to take it easy - and I suggest you do. (apparently some reccomend 40 laps to learn the track before attempting anything brave), keep right, with right hand indicator on.
Always keep one eye on the rear view mirror, as cars that are out for lap times will appear out of nowhere, litteraly nothing in sight one moment and next bend you can find one on your arse.
If you are taking it slow, dont take the racing line on corners with traffic coming from behind.
As it is classed as a public road, not specifically a track, if you are slower and on the left and you get hit from behind, then it is YOUR fault.
A great tip I was given when there for the first time was to go out just before closing time - its a lot quieter.
I was in two minds whether to go round at all before getting there, but after one lap my nerves were calmed.
If you can find a friendly face then you could blag a passenger lap with someone just to get an idea of the track.
Above all, just have fun