Bring rice, salt, and water to a boil, then reduce heat, cover, and cook for 15 minutes. Let sit covered for 5 minutes, then fluff and stir in lime zest, juice, and cilantro.
Heat olive oil in a skillet, cook onion for 5 minutes, add garlic and cook 1 minute. Add ground beef and cook until browned, about 7 minutes.
Stir in tomato paste, taco seasoning, and water; cook for 2-3 minutes until saucy.
Divide cilantro lime rice among bowls, top with beef, beans, corn, tomatoes, and lettuce. Add guacamole and lime wedges, then serve.
Notes
You can customize toppings and spice levels to your preference.