Prep the pork: Pat the pork dry and remove the fat cap (optional). You can also leave it on or remove some. Cut into 4-inch cubes. If using a bone-in cut, cut around the bone.
Add pork to a slow cooker/crock pot. Season all over with dry spices. Top with orange juice (toss orange in), coke, onions, and garlic. Stir, cover, and cook for 4-5 hours on high heat or 7-8 hours on low heat.
For the pickled onions: half the onion and slice into thin half rings. Bring vinegar, sugar, and salt to a simmer in a saucepan. Immediately pour over the onion and sliced jalapeno in a heat-safe mason jar. Cover and keep on the counter for 30 minutes. Once cool, transfer to the fridge.
For the guac: mash avocados with salt and lime juice, stir in onion and cilantro. Stir in the tomatoes last.
For the corn/beans. Rinse/drain beans and corn. Heat oil over medium heat. Add beans, corn, and cilantro. Season with salt and saute until heated through.
Transfer pork to a baking sheet with a slotted spoon. Using your hands or two forks, pull into bite-sized chunks (it should easily fall apart). Drizzle with some extra juice from the slow cooker and broil on high for 2-3 minutes to crisp.
Cook rice according to the instructions on the package. Serve carnitas over rice with corn/beans, cheese, guacamole, pickled onions, cilantro, and lime wedges.