Advice for my rescue dog.

So last Saturday I adopted a 3 year old half English bulldog, half pitbull mix. He was found outside in the winter, abandon in New York State (very cold), and had lost a lot of his hair, scratches all over him and was in very bad shape. After some time he’s doing so much better, regrew most of his hair and has been a sweetheart to me. So a few questions I have, he keeps having accidents in the house and I can’t seem to figure out a good routine yet, I work Monday-Friday but I’m able to get home on lunch to let him out. So would it be better to feed him once a day rather than twice? Because in the morning he will eat but I can’t get him to go poop, so maybe if I feed him once after work that would work better because I’ll be home with him to let him out when he’s ready, Any advice would be really great, thanks so much!