Bring a large pot of salted water to a boil. Add the spaghetti and cook according to package instructions until al dente, about 8-10 minutes.
While the pasta cooks, heat the olive oil in a large skillet over medium heat.
Add the minced garlic and red pepper flakes to the skillet and sauté for about 1 minute until fragrant, stirring constantly to avoid burning.
Add the sliced zucchini to the skillet. Season with salt and black pepper. Cook, stirring occasionally, until the zucchini is tender and lightly golden, about 5-7 minutes.
Drain the cooked pasta, reserving 1/2 cup of the pasta cooking water.
Add the drained pasta to the skillet with the zucchini. Toss to combine.
Add the reserved pasta water a little at a time to loosen the mixture and help coat the pasta evenly.
Stir in the grated Parmesan cheese, chopped basil, chopped parsley, and fresh lemon juice. Toss well to combine all ingredients.
Taste and adjust seasoning with additional salt and pepper if needed.
Serve immediately, garnished with extra Parmesan and fresh herbs if desired.