The red start is the busiest one. Blue is quite nice as it is ballot places and club runners so very few people in costumes and a lot of them understand how races work.
You will find out your pen number when you get your race number at the expo. It is the small number in the bottom corner, typically from 1-9.
You don't have to get into your pens until quite close to the start. You can start in the pen that is designated to you, or any pen behind that. So if you are assigned pen 4 but your friend who you want to run with is in pen 7 then you can both start in pen 7 together, but he cannot move forward to pen 4. There are marshals at the entrance to each pen who will help you if you are unsure, and they will only let you into the correct one. However, having done that role I can tell you that a heck of a lot of people try to take the piss and the mashals sometimes have to physically create a barrier to prevent people doing what they like. By the time the race starts they have lost all sense of humour so please be kind to them.
About 5 min before the start the tape seperating the pens is cut so that everyone is bunched up in one big long line.
And don't forget that it is chip timed, so if you do miss the start then you can join in at the back and not be penalised for a late start.
