pool opening

Opening up pool , recent widow, hayward EC65 Inground pool, we cleaned all fingers and filter system last year at closing, do ineed to backwash as well or prime pump?

You will need to prime pump unless the return line in low enough for the pool to self feed. Just remove top cover from filter and fill the  intake basket with a pail of water. That should be enough to get it started assuming you have the drain plugs leak tight and the top filter cover on and sealed. It’s usually a good idea to lubricate the seal with, even vasoline. If the filter was clean when the pool was closed I see no reason to backwash yet. Just let it run until the water clears. You did not mention anything about pool size, but you need to add shock. My pool is 18x39 and I usually use 5 or 10 gallons of liquid shock t o begin with. Good luck.