Best and less painful positions for losing virginity

Hi my name is Russell me and girl freand have been thinking of sex I am 28 she is 19 we where messing around and I asked here because she.felt really tight if she was a virgin she said yes I told her I want to wait before sex I really like her and I dont want to hurt her I really think I love her and dont want her to be in pain I am a bit bigger is there a way.to do this without hurting her I was thinking about her on top so she can go at her pace I just want her to be comftable and enjoy it any suggestions