@cockapup it's not too late. I would start by luring her into the crate. If he won't go in for a bit of kibble, make it a bit of chicken, or hot dog sausage, or cheese....whatever he'll go in for. Hold the treat through the crate bars towards the back of the crate, so that he has to go into the crate to get it from you. Give great praise when he does, or if you've used a marker word for training, use that (e.g. 'Yes'). You need to repeat this step over and over again, until he's freely walking in and out of the crate without hesitation.
Then, you can start to close the door, but only for a second. Once you've done that, open it and say 'yes!' and encourage him out of the crate with a treat. So you're making it a bit of a game. He gets a treat for going in, and for going out. Once you've done that a few times, you can start to increase the time, in increments, that the door is shut.
Once they're crate trained, it makes things easier. Now, we don't have the crate door shut. We have a pen around the crate, and Hazel can wander into her crate, lay down, sleep, etc. She might get up and wander out to have a drink, then flop on the floor, then go back to her crate....she knows it's her safe sleeping place.
Re. the biting, how much sleep is he getting? He needs about 20 hours sleep per day at this stage and we always knew that Hazel was overcooked if she started to bite. Bitey puppies are tired puppies.