Help with a new cat! Troubles at night and with litter box

I recently started fostering a sweet 2 year old boy, with the option to adopt after 2 weeks. I’ve never had a cat before, and I loved his friendly and cuddly personality. He’s sooo sweet but he has the worst litter box habits: he’ll jump in and out of it constantly and throw litter everywhere. He also constantly disturbs my sleep with constant meowing and zoomies which has really not been a good time these past couple days. He started pooping on the floor even! I live in a tiny apartment which makes it worse. I would say that he’s just having trouble adjusting but he’s so confident and cuddly walking around the house. I want to make this work, any advice?