Ahhh, the Turkey Woods!
I have been hunting turkey a few years now and my wife hates me in the Spring and Fall now. I am in the woods taking pictures, scouting, planning my next hunt or just plain old watching. I love turkey hunting. You will too. Everyone here that recommended patterning your gun is 100% correct. Different loads will absolutely pattern differently at all ranges. I like #5 in 3" or 3.5" shells. Your 500 will only use 3", but that is an ideal shell. I took three toms with #5 shot that was 1 3/4 oz in a 3" shell. One bird was taken at 10 yards. One shot drop. I load one shell weather I am using my semi-auto or my single shot. It makes you strive for the best shot. You will find that your gun will pattern best around 30-35 yards with a #5 or #6 shot in a 3" shell. Something nobody has answered yet is what type of pattern you are looking for. Get yourself some turkey targets and aim for the neck where it meets the head. You will need a MINIMUM of 6 vital hits to drop your bird at no more than 40 yards. Measure a range out and practice like crazy. Stay with the same brand and size of load once you find one that works best in your gun. I always pattern at 40 yards, because it is the most extreme I would normally get in a hunt.....although I had a stubborn tom this past Spring that I took at 58 yards. I could not get him to come any closer. I was confident because I patterned my gun with the particular load. I was using Winchester Supreme 2oz Turkey loads in a 3.5" shell. Brutal on the shoulder, but deadly (deadlier) down range. The bird lost all muscle control in the neck and died quickly after a short jaunt with his neck behind him.
In any event, turkey hunting will help you refine all of your hunting skills, because they are SURVIVORS and can see you even if you can't see them. I spooked several of them just by subtle hand movements. Remember that they are always on the lookout for predators, and you are a predator. I have been fortunate enough to be able to SIT STILL for hours and make the shot. I have been blessed to see several hens yelling back at my calling and work their way out of the woods to peck at my decoys. I have startled toms right out of their roost in the first daylight with ONE CHIRP of my slate call and the hunt was over in 13 minutes. As I said, FORTUNATE, because I have seen many more walk away from me....or never come near me.
Don't ever get confident, pattern your gun, get good camo, pattern your gun, learn to talk turkey, pattern your gun and finally pattern your gun. Good luck!
P.S. In NY, you can only use #4, 5 or 6 shot. Practice with these loads as they really are the best for MOST scenarios. #5 is my favorite, but they are all deadly at the right ranges.