Kathy, did you have to reconnect the plumbing to the pump and filter when you opened? Are you sure the hoses are going to the right places? You should have a pipe going from the skimmer into the side of the pump strainer basket housing, then a pipe going from the top of the pump to the filter. Take the hose from the pump to the filter off at the filter end and point it toward the pool and have somebody turn the pump on. You should see a bunch of water if the pump is working.
Also have you removed the winterizing cap (if installed) from the return? If so, and you got water flow above, put that hose back on, and take the hose coming out of the filter off of the pool wall and repeat the test. Make sure the filter is set to filter or recirculate.
ETA: Jason and I are on the same path but from different sides of the filter.