Cook beef, onion, and bell pepper in a skillet over medium heat until the meat is no longer pink, about 5 minutes; drain. Stir in garlic, basil, oregano, salt, and pepper; cook and stir until fragrant, about 2 minutes. Add tomatoes and cook until warmed through, about 2 minutes. Stir in squash; cook until liquid has evaporated, about 10 minutes.