Tell your crew, "If you don't know the enforcement or the signal, then don't throw your flag." 
I tell my crew (with a smile on my face) "if you're going to call something goofy, you better be able to tell me the signal and the enforcement, or I'm going to wave it off." My first game as a WH (8th-grade game) , the very first flag thrown in the game was a dead ball foul for failure to wear a mouthpiece with the snap imminent. I think I signalled "dead ball", "delay of game", "helmet contact".

Lean on your U. Ask him to keep you out of trouble. Take your time, don't rush the RFP, have fun.
Great advice. A good LJ will help with clock status after a penalty, too.
After the game the only comment from my crew was that I should slow down when giving the signals. All-in-all it went well.
I'm still getting that comment myself. I'm getting better though. Glad it went well, Mike!