Heat oven to 425°F. Line a large sheet pan with parchment.
Toss squash with olive oil, chili powder, cumin, paprika, garlic, salt, and pepper.
Spread squash on the pan. Roast 25–30 minutes, stirring once, until browned and tender.
Warm black beans in a small saucepan over low heat. Season with a pinch of salt.
Mix onion, cilantro, and lime juice in a bowl. Set aside for topping.
Warm tortillas in a dry skillet or wrapped in foil in the oven.
Assemble tacos with beans, roasted squash, avocado, cotija, and the onion-cilantro mixture.
Finish with extra lime juice to taste. Serve immediately.