TTC but I need opinions......

So I am almost 21 and my boyfriend is 42. We are hoping to have a baby of our own because that's what we both want. I know people have their own opinions of the age thing but we both love each other, he is my whole world. He has 2 kids with his ex, to which his youngest is almost 5. So my question is, is he too old to have children now? Like his sperm count and what not? He is healthy and everything. We just want to know so we don't get our hopes up if we don't conceive. Also any tips for either of us?