How can I get my puppy to stop crying?

I have a 7 month old Australian Shepherd border collie mix and we will be moving into an apartment in either late sector early January. I do crate him as he can’t be trusted out alone and I currently work and go to school online. He’s usually fine when I first leave but sometimes when I come back home I’ll hear him crying or barking especially if he hears me talking or if I don’t come to him right away. The only other times he cries is when he wants something or wants to go outside but how can I stop him from doing this when I’m gone?