Kissing my boyfriend for the first time?

My boyfriend and I are hanging out this weekend. I'm 14 yearsold. Were probably gonna kiss and it'll be my first kiss. He's actually experienced! He's even made out before and he used to date one of my close friends and she told me he was a good kisser! Im so nervous! What should I do to prepare? How do I show him that I wanna kiss? What if we start making out.. what do i do with my tongue?