First time!! help

Ok girls I need advice! My boyfriend soon to be fiancé next summer. We have both decided to wait till marriage to have sex, I am nervous about our first time like we sext a lot and he tells me stuff he wants me to do like ride him and give him a blow job. I'm nervous about the pain and the blow job!! Any ideas on how i can not be nervous and about the blow job? I don't know how I feel about his dick in my mouth or him cumming.