Keep the caps on the windage and elevation turrets when not adjusting to protect from moisture and dirt.
Before shooting, the scope must be properly mounted to the rifle. How To Sight In Your Rifle Scope bushnell 3-9x40eg manual
Never wipe dusty lenses with a dry cloth or your t-shirt, as small dirt particles can scratch the optical coatings. Blow away loose dust first, then use a dedicated microfiber lens cloth or an optical lens pen. Keep the caps on the windage and elevation