Be certain the scope is OFF before you plug it in, then plug it in and turn the light on full. Check to see that the filter holder is fully in or fully out. Otherwise, you will not be able to use the scope. Filters only serve to lessen eyestrain over long periods. Lenses may only be cleaned with lens paper.
Paper towels are okay for slides.
Position the revolving nose cone so that the smallest magnification objective lens clicks into place over the opening in the stage or platform below it. The total magnification of your scope is the product of the objective lens magnification and the magnification of the eyepiece lens. Place a slide horizontally into the stage clip of the platform. If there is printing on the slide it should be placed so that you can read it. At low power, you can safely focus the specimen using the coarse adjustment.