For guys, by most accounts, the first time is a quickie. Most guys I talked to estimated their first time lasted about 1-3 minutes. So coming quickly is nothing to be embarrassed about. If you're with another virgin, you really don't have to worry. Most men and women, however, find that the missionary position works just fine for that first test run.
Many novices worry about rhythm.
Rhythm is something that comes with practice, and from getting to know how your partner moves. I didn't really get the motions going. I never practiced on an apple pie or anything. Slap on some tunes. Sexy tunes, that is.