Sex isnt a bad thing.. in another one of your posts you talk about feeling dirty after messing around with somene.. once you get over this everything should starting going well..
First thing is you need to be comfortable with your sexuality and with being sexual with your girlfriend. Your being comfortable will help her become more comfortable with her sexuality..
Maybe not with this chick, but once you are older and are more comfortable with yourself, you will show the girls how you liked to be jerked off or whatever, you will talk about what each other likes, and sex will be great..