He will cum.
I will bet every cent I own that he will orgasm when you have sex (unless he has some medical issue). Seriously, you do not need to worry about that. Not at all. Honestly, there’s a better chance of you being hit by a bus while on your way to have sex with him than him not cumming.
Focus on yourself in the beginning because you’re new to this. Focus on your pleasure and what works for you. That’s your number one goal. Once you start feeling more confident, you can start taking more control over things in bed and feel better about taking turns “driving” with him. He will benefit from this approach just as much as you will.
(From the peanut gallery: denjiro7 said: Additionally, if the guy doesn’t cum, it’s more likely due to issues HE is experiencing than anything you are doing.)