Cumming in condom

I’ve only had sex once before and I’m planning on doing it again soon. I don’t remember what I did with the condom the first time I had sex and he came. I heard you hold it at the base so that it doesn’t slide off, is that true? Or does he withdraw a bit before he cums? (I’m not talking about the pull out method by the way)

What do you do? Please help.