I'm 21 years old I've been sexually active since I can remember, and never was interested in getting or giving a blowjob. But now, I want to but don't know how to give oral sex in a way I know he will ejaculate. So I just open my mouth and then what?

I don't know if I'm your average 20 year old. (virgin and only had one b.f.)I have never been able to insert a tampon correctly, nor have I ever looked at my own va-jay-jay. I recently shaved it for the first time. I really don't know what the call is for anything relating to my womanly junk, you know? I don't know if I should leave the hair down there, wax, or completely shave it all off. I don't know how to insert a tampon, and I am worried when it comes to sex it just wont fit. I even tried with some dildos and can't fit it in, but I don't even know if I'm doing it right. Please, please help me! Those pictures on the tampon box just don't work for me!