Bulldogs are super laid back. I think that literally their only drawback is that they snore.
Lab mixes are my go-to. The lab in them makes them very attuned to their people, and the mix often helps them not be as neurotic as purebred labs.
Some pit bulls are very chill, you just have to walk them extremely religiously to get rid of their energy. They are pretty much the best dogs with kids.
My mom swears by her old college dog’s breed, the Australian Cattle Dog. They can be nippy around kids without training, though.