In a medium pot of boiling salted water, cook orzo until al dente, according to package instructions. Drain well. Spread on a rimmed baking sheet to cool completely.
In a large skillet, heat 1 tablespoon oil over medium. Add zucchini and garlic; season with salt and pepper. Cook, tossing occasionally, until crisp-tender, 4 to 6 minutes.
Transfer orzo to a medium bowl; add zucchini mixture, basil, vinegar, and remaining teaspoon oil. Season with salt and pepper; toss to combine.
If storing, cover and refrigerate up to 1 day; bring to room temperature before serving.