Almost every guy has an "awkward" first time.... in one way or another...
Feelings of anticipation, performance, and anxiety are all pretty normal.
One other thing though about how you worded your post - Approaching this activity with the attitide of "I need to measure how well I do" is the wrong mindset. If you are "looking to have sex" as oppossed to sharing love with someone you care about, your bound to have a very dissapointing first time.