JACK-OF-ALL-TRADES
A person who can do a lot of things, but can’t be called a pro at any of them. They’re like a kid who can run, jump, and climb, but can’t win a race.
He can write, design, and play guitar, but none of them is good enough to be a pro.
She can cook, clean, and paint, but none of them is good enough to be a pro.
He can fix cars, build decks, and mow lawns, but none of them is good enough to be a pro.