If you're looking to level up quickly and earn more bricks the right way, here are the most effective :

Don’t rush to high-level zones immediately. Quickly clear out the small buildings in the starting area to buy your first few weapon and backpack upgrades.

Prioritize upgrading your weapons over your backpack size early on. Breaking things faster is more efficient than carrying more at a slow pace.

Instead of hitting one wall at a time, aim for the base of structures or the center of a group of objects to maximize the destruction per hit.