Trump has, overall, done nothing good, except maybe one or two small things by accident. Like engineering a prisoner oversees to be freed. But you can be sure that in these situations, he's been coaxed by someone else. Or bribed.
Trump is the only president about whom I can say nothing positive. He has no friends in the ordinary sense of the world. He is estranged from much of his family. (He once pushed to get his nephew's medical insurance canceled, and tried to tamper with his father's will.) He is appallingly ignorant. He is horrifyingly rude and cruel. He hires incompetent people, basing his choices mostly on their loyalty and money. His criminality is staggering.
By comparison, President George W. Bush was widely disliked, but at least you could feel he had some decency. He loved his family and had genuine friends. His military actions were appalling and stupid, but I believe he was sincere in caring for the country. He was under-qualified (though certainly more qualified than Trump!), but he drew on his father's circle (his father having been President George H. W. Bush) to choose competent people.
President Richard Nixon, who was widely considered the most corrupt president ever at the time, seems almost angelic by comparison. He was smart, experienced, and promoted a lot of good governmental programs.
If you find any Trump supporter citing anything good that Trump has done, you can be fairly sure that they're slanting the truth.