awe sweetie...don't worry. don't even give any of this a second thought...the reason is that you need to do what ever you feel like doing at the time. this stuff can't be planned. if you love him and you want to make love to him then just do what comes naturally to both of you. i doubt it will hurt, but be cautious and go slowly.
the main thing is just to relax, take your time, have plenty of time (NO TIME FRAME TO WORRY ABOUT) and just do whatever feels good and makes you happy.
anything 2 people do while loving eachother physically is awesome...so don't sweat any of it. don't worry about being good at it or not good at it. just have fun and relax. also one last comment...don't forget to allow your humor in (probably the last thing on your mind right now, but seriously)...because sometimes funny stuff happens. don't be afraid to laugh about it. if someone farts, don't freak out...just laugh...if you bang your heads together, just laugh it off... don't take the experience or yourselves too seriously.
the fact that your so comfortable with him is a HUGE PLUS. good luck sweetie...let us knwo how it goes ok?
jasmine