Shrimp Tacos with Avocado Crema

Name: Shrimp Tacos with Avocado Crema
Ingredients: 1 ripe medium avocado, halved and pitted; 1/2 cup roughly chopped cilantro, plus 2 tablespoons, divided; ¼ cup sour cream; 2 tablespoons rice vinegar, divided; ¼ teaspoon salt, divided; ¼ teaspoon ground pepper, divided; 2 cups thinly sliced red cabbage; ½ cup shredded carrot; 1 scallion, chopped; 1 pound large shrimp (21-25 count), peeled, deveined and cut in half; 1 teaspoon chili powder; 1 teaspoon ground cumin; 1 tablespoon avocado oil; 8 corn tortillas, warmed; Lime wedges for serving