Unless you’re a middle-aged adult (and I suspect you are not), I would strongly urge you not to pursue a crush with someone this much older. Not all crushes have to be acted upon. You can admire your crush from afar, as we do over distant movie stars none of us can realistically have.
It’s much easier and more appropriate for you to pursue a potential relationship within your age group. You’ll have much more in common with guys your age and find that conversation flows so much easier. I would never recommend that teens in particular date someone outside of perhaps a two-year age difference. The maturity gap and expectations can be substantial. You can get yourself into trouble quickly and not even see it coming.
Stick with someone your age. You’ll worry less about nervousness and will be able to be yourself.