Preheat oven to 400 degrees Fahrenheit and line a large, rimmed baking sheet with parchment paper for easy cleanup. On the baking sheet, toss the whole cherry tomatoes and sliced zucchini and squash with 2 tablespoons olive oil. Sprinkle with salt and pepper and arrange in a single layer (or as close to a single layer as possible). Roast for about 25 minutes, tossing halfway, until the cherry tomatoes have burst and the squash is tender.