Question about blow job

Help ladies!

So when I give my boyfriend blow jobs, he says I get him close about 7/10. I do not know what I am doing wrong, I have asked what I am doing wrong, he says using too much teeth or my mouth is cold. I need advice on more how to get him off because I don't know how to too really, what do you do to get your man off? Or what helps you to get him off, this is my first guy to give blow jobs too, and this is his first time receiving any. So we are sorta new to this part.

Thanks,

Courtney K.