Lean on Pete (2018) on Netflix

Plot summary

Charley Thompson, fifteen, has just moved to Portland, Oregon, with his father, Ray. Out on a morning run past a racetrack, Charley comes across a stable and picks up casual work there, looking after a racehorse. The horse, Lean on Pete, belongs to Del, an ornery trainer who hands Charley the grunt chores and tries to bond with him by giving him a pair of boots and showing him table manners. Del's top jockey, Bonnie, rides Pete. Charley tells Del that he never knew his birth mother and that his father keeps him from Aunt Margy, the only maternal figure in his life.