Need some advise!

So I am fifteen and Christian so I want to stay a virgin till marriage I have met this guy and he is the sweetest most amazing guy I have ever met , we have been dating for about months , in the past I have been sexually assaulted and he knows that so he is always very careful and sure to ask when he wants to touch me he understands that I want to stay a virgin until marriage and respects that .

Anyways we are going to hang out this weekend and we were talking about what we would do , so he was asking me if I would be comfortable to give him a blow job and I said sure.

I'm really nervous.

I have no idea how to do a blow job but I really want to.

Please give me some tips?

Also he isn't pressuring me to do anything this is all by my own choice