Why Does My Kitten Keep Crying?

I’m wondering why my kitten keeps crying. He’s only 7 weeks old and I’ve had him for about two months now, but he cries sometimes when he doesn’t get his way (like trying to play with a toy) or if someone leaves the room. It makes me feel bad to see him cry like that because I don’t want anyone else in the house to be sad around him. Is there any advice you can give me? Thanks!