First time down the track
Probably the best advice I could give you is to find an experienced local racer, however casual, and have him show you around. Teach you how to stage. If the track will allow it, might be beneficial to make a SLOW run so you know what to expect in the way of traps, turn off, return road, etc.
If all you are interested in (to start) is "see what she run" don't get too hung up, for now, on the yellow/ green. For ET and speed readings, you can "sit" at the green for a few seconds and it won't matter. The clock starts when your front wheels leave the stage lights.
What size rear? 7 1/4? 8 1/4? Even and 8 1/4 "open" rear is easy to break (spider gears) if you get carried away on launch, or start to wheel hop.