Concerned about my ball python

[Alx]

Got my baby ball python jan 31st first time owning a snake and all I've been doing latley is worrying about it. Right now the thermometer reads 88 there's also a under tank heater and a bowl with water and a hide. I've done a lot lf reading but my concern is with it's feeding it hasn't eaten since I've got him and I don't know when he was last fed. I offered it a pinky but it didn't seem at all interested in it, I know snakes can go a while without eating but it looks rather thin. There's kinda a fold of skin that runs along the side length of the snake. I haven't tired feeding it again because he is in shed but I hate worrying about him dying! He moves about a few times a day and seems strange to me that he enjoys laying out in the open over his hide unless the under tank heater which sits under his hide is too hot. I find myself knocking on the glass or making sure it's still breathing. Just a bit ago I knocked on the glass and got no response, I know knocking on the glass isn't good as it might stress it out but I can't help but want to make sure it's alive. I picked it up and it became active so I'm not sure if it might have just been sleeping. I've done a lot of reading and had his enclosure set up before I got him but the fact that he hasn't eaten since I've gotten him and looks a bit on the thin side worries me too much. Any advice would be greatly appreciated.