Heat oil in a large soup pot over medium heat then add carrots, zucchini, and onions, season with salt and pepper, and saute until tender, 8-10 minutes. Add garlic then saute until very fragrant, 1-2 minutes.
Add chicken broth, marinara sauce, Italian seasoning, and red chili pepper flakes then turn the heat up to high to bring to a boil. Once boiling, add meatballs and pasta then stir to combine. Turn heat back down to medium then simmer until pasta is tender. Ladle into bowls then serve.
Notes
I don't recommend reheating gluten-free pasta as the texture deteriorates.