I got gifted this succulent a few days ago. I’m a first time plant owner so I’ve been doing a lot of research but I’m very much in need of guidance. I’m not sure what care if any was given to him before I got him.

I repotted him with a 1:1 mix of cacti/succulent soil and Perlite as I read that was good. I had to keep him in the small plastic pot he came in as the only ones I could find were way too big for him (though I have them for if/when he grows). The soil he was in originally was a bit damp, but I’ve no idea what root rot looks like to know if he has it. Before I repotted him his leaves were looking wrinkly and less bright green than they were the first day I got him, and a few leaves on one side were turning a pink-ish white. The day after that, the pinkish leaves turned brown-ish, and the other leaves were still wrinkly. This morning I switched windows to see if he’d do better elsewhere as I’m not absolutely positive he’s getting enough light (or if hes getting too much?) and now the leaves are less wrinkly but the brown leaves are browner and sadder. Can someone give me any tips to know for sure what caused this or how to help him? I appreciate anything, thank you!