1. To prepare salsa, combine corn, jicama, black beans, cilantro, 1 tablespoon juice, 1/4 teaspoon cumin, and 1/4 teaspoon salt in a small bowl; toss gently to combine. Cover and chill.
2. To prepare guacamole, combine avocado, 1 1/2 tablespoons juice, and 1/4 teaspoon salt in a small bowl; mash with a fork until well blended. Stir in tomato. Place a sheet of plastic wrap directly on avocado mixture; set aside.
3. To prepare tacos, combine chili powder, oregano, 1 teaspoon cumin, and 1/4 teaspoon salt in a shallow dish. Add pork to spice mixture; toss to coat.
4. Heat a large nonstick skillet over medium-high heat. Coat pan with cooking spray. Add pork to pan; sauté 4 minutes or until done, turning occasionally. Remove pork from pan; keep warm.
5. Wipe pan clean with paper towels; recoat with cooking spray. Add 2 tortillas to pan; cook 30 seconds on each side or until soft. Remove from pan; keep warm. Repeat procedure with remaining tortillas and cooking spray.
6. Spread about 1 1/2 tablespoons guacamole onto each tortilla; top each tortilla with about 1/4 cup pork and about 2 tablespoons salsa. Fold tortillas in half.