Hey, that's not too bad. I can see logan in this one. You kept it quite clean. Maybe you could get a little more into details, adding more wrinkels (idk if spelled right). References help out a lot. You just gotta take your time.
You should try sketching more. All your drawings seem to have some pretty hard lines, this gives you very little space for correcting and adjusting. If you sketch your drawings more it allows you to adjust proportions on the spot.
Softer lines are also better for creating little wrinkles without having them stand out too much. I'd recommend you'd use a softer pencil like a 2B.
Anyway, keep it up. Don't stop until DD knows everyone you hang out with.