That wasn't your opponent's first fight, for sure. He's been around for a while ?
Covering up and standing still just turns you into a punching bag. Don't do that. Cover and move, or just move. But don't just cover and stay still.
Find the right time for your strikes. Notice how often your left hook would land when he would try strike with his right side early in the first round? Notice the right hook over his jab at 1:51ish of the first round?
Don't just throw to throw. Now when and why for each strike. It'll take time to learn but it does become instinctive.
Good fight man, good courage. Your opponent was miles ahead of you in terms of experience I bet you, so you did as well as you could have.