How to dance at a nightclub if you don't know anything about dancing:
Step 1. Get a girl.
Step 2. Get up close. Plant your hands on the girl's hips, from behind. You need to be right up close, chest-to-back, don't let there be any space between you.
Step 3. Let her lead, she probably knows how to dance better than you do.
Step 4. Mold your movements to hers. When she gyrates her hips, just follow her movements.
Step 5: You look like you're dancing, now. Great job.