Just adopted a cat today in honor of clear the shelter !!!

What am I doing wrong ? My fur baby who is 3 months going on 4 is hiding From me . But yet doesn't mind if I pick him up like that . He gives me that look with his eyes which are watery :( he was in the box for about 30 mins prob while I went to get toys I thought it was okay to let him be in the family room but I was wrong he just wanted to hide it took hours to get him out the sofa. Now he behind the toilet in his new sleeping quarters for the night 😲😵. He didn't even meow at me yet just looks at me. I left some food and water and his litter box and a bed in the bathroom so he can have some time to himself . He was brought to the shelter by his foster mom who he had two other siblings I believe but she said he is independent. Any advice on what to do from here on out this my first cat.