Some good general advice
Have lube handy
Know your body, know how it works, know how your contraception works, know what you like
Talk to your partner, before, during and after, good communication is very important for good sex
Don't expect your first time, both losing your virginity and first time with another person, to be amazing. Don't expect to orgasm (either of you) if one or both of you does great, if not, don't stress. Your first time (first few really) is about being close to another person, getting to know their bodies and how your bodies work together. Its unlikely to go perfectly, and that's OK.