I cant make him cum!

Okay so, i've been with my bf for two months now and i gave him oral sex for the first time last Saturday.
He said i was good and he liked it a lot, but he came just with the help of his hands! Like.. I didnt do anything to make him cum.. Later he told me to not worry, that i was good.. But idk
It was my first blowjob. How do you do that like whats the secret of a perfect blowjob?