Need help having sex. how do you do it?!?

my bf and i are both virgins we have been dating for almost 4 years. we are 19 years old and cannot seem to get it in. whenever things get heated up i always get a tingly feeling in my vagina and need to stopp. i feel so bad for him ): idk what to do! he cant seem to find the hole either. usually he is on top because if i go on i get scared and jump or i get to excited and need to stop. anything i can do?!