First Time (Sex)

so yeah. i had no idea where to post this. but maybe here is okay.

i was wondering what people's first time was like. whether it be with a guy or with a girl. i've never slept with a guy or a girl, and my girlfriend hasn't either. and we're both kinda getting to that point where we might have sex soon. but i don't know how to approach it or how to act or anything. can someone please help me out on this one.