For a start some info would be helpful:
--Above or in-ground pool? Defines the equipment location as being above or below water level.
--Filter type? Model would be nice as it may define the valving positions.
--Pump model?

If you have any blockages the pump won't prime. As Michael said could be just valving.

If you do get the thing going check for leaks all around.

Post the info and we'll go from there.
Al