I think the original 5/3/1 with the BBB assistance work is a great starting point. You could do First Set Last or 5s progression or something like that if you’d want. Really, you can’t go wrong with any of the one’s Jim Wendler has put out, it all works.
I’d make sure to get in some conditioning work as well. Prowler, sled, hill sprints, loaded carries, just something to get you moving.
I personally would work less about cutting fat, gaining muscle, etc etc and focus more on this point on building sustainable and healthy nutritional habits. Focus on eating some green veggies with every meal. Focus on getting your protein from meat and eggs. Focus on sticking with potatoes and rice as carb sources. Just get back to seeing food as fuel rather than getting obsessed with bulking and cutting.
This is my go-to reference for diet.