I would like to go further with a boy i like! Im very inexperienced.. never gived a ******* or anything! Soo.. I'm embarrassed, because he knows his stuff! If ever we try to have sex, I'm scared he wont fit? How do I know?

if your scared talk to him about it first and if you both still want to give it a try then talk a deep breather and trust and have fun. You should ask the question if it doesn't fit would you still want to be with him you will you feel embarrassed for him but if you choose to stay after then kick back and enjoy your relationship because sex isn't the whole relationship