Crush doesn't equal being in love so I'll answer both questions.
How do you know if someone is in love with you? You don't. People express it in many shapes and forms. No real answer there.
As for making a move on your crush, just be you. Do it. It's your own personal delivery. I always make the first move and I'm usually attracted to feminine types so I always have this creative way of making a move. IDK your situation specifically. So good luck tbh and if he rejects you, move on
