If you have an above ground pool, and the filter isn't located way uphill, then it should fill up with water naturally because the water is above the pump and filter. If you have any shutoff valves in the lines to and from the pool, make sure they're open. Then turn the valve on the filter to "rinse" and turn the pump on. The pump should start pumping within a couple seconds and all the dust from the sand should wash out the waste pipe. When it looks clear, shut off the pump, turn the valve to filter, and turn the pump on. Boom. You're in business.