Thank you for rescuing this little one.
I don't really know what to say except maybe after he gets used to you and his new home, get an expen or keep him in one area and slowly move the pad towards the door to get him potty trained outdoors.
As for pottying in his bowl, maybe pick his bowl up when he's not drinking and put it down only when he needs water?? Maybe put it by the pee pad and keep an eye on him and put him on the pad when he shows signs of peeing? Then praise and treat when he uses the pad?
Also, I guess when he does go outside, really praise and treat so he can associate it with going outside. Best of luck.