In a slow cooker, place pork roast and rub with salt, pepper, paprika, onion powder, and garlic powder. Pour beer over top, cover, and cook on low for 8 hours.
After 8 hours, remove lid and shred pork with two forks or pair of tongs. Toss well with beer then cover and cook for additional 15-30 minutes. Season with additional salt and pepper, if needed.
Avocado Cream:
Place avocado, lime juice, sour cream, and cilantro in food processor and pulse until smooth and creamy.
Taco Assembly:
Assemble tacos by adding pork to each flour tortilla. Top with cabbage, then drizzle with avocado cream, and finish off by adding few extra chunks of diced avocado and crumbling queso fresco on top.