Cook the linguine or spaghetti according to the package instructions until al dente. Drain and set aside.
In a large skillet, heat the olive oil over medium heat. Add the chopped onion and bell pepper, sautéing until softened, about 3-4 minutes.
Stir in the minced garlic and cook for an additional minute until fragrant.
Add the shrimp, mussels, and scallops to the skillet. Sprinkle with Cajun seasoning, smoked paprika, salt, and pepper. Stir well to combine.
Pour in the vegetable broth and add the halved cherry tomatoes. Bring the mixture to a simmer, cooking until the mussels open and the shrimp turn pink, about 5-7 minutes.
Add the cooked pasta to the skillet, tossing gently to combine everything evenly. Allow it to heat through for an additional 2-3 minutes.
Remove from heat and garnish with fresh parsley.
Serve with lemon wedges on the side for a zesty finish.