First Steps Achievement in PowerWash Simulator

Before you absolutely do anything else in the Backyard, you're going to want to spray the 12 stepping stones, which can be found on the top patio leading from the gate to the patio itself (near the dog house). It's relatively easy, this one, as there's nothing super sensitive you can splash close by that would invalidate the achievement, because you only need to "complete" the 12 stones before you complete anything else. Yes, you can splash other stuff, just make sure you're not too unwieldy and somehow spray something else to completion.