Heat the marinara sauce and meatballs, covered, in a small saucepan over medium-low heat, until heated through, 12 to 15 minutes. Meanwhile, cook the spaghetti according to the package directions. Drain and transfer to a bowl. Spoon the meatballs and sauce over the top.
How the heck is this a recipe? This is like having a recipe for rotisserie chicken and the instructions are to go to the store and buy a rotisserie chicken.