What do I do when having sex for the first time?

Im 18 and I have never had sex with a girl and its kind ofemmbarrassing.But now that I found a girl I want to do it with I'm afraid Imma do it wrong, look stupid or look totally unexperienced...What do I do???

Well for starters, take things slow. Never rush sex, whether it's your first time, fifth time, or hundredth time. Foreplay is critical for properly pleasing a woman. Take note of what she does when you start, for example, look to see if she's being verbal or not. It's kinda weird if you're talking and she's just silently enjoying it, and vice versa. So mirror her. Also, if you're worried about rhythm, play some music. A lot of people have intercourse to the beat of a song. Something that's not super fast though, make sure it's got a good tempo to it. Besides that, just stay calm and make sure you meet all her needs, but at the same time remember that it's for both of you, not just her.