Joined A Bullseye League

Starting January 5th, I will be shooting Centerfire Bullseye at a local club here on Long Island. Haven't shoot competitive pistols since the 70s and don't expect to do very well, but it gives me a reason to go out and shoot with a bunch of like mined gun owners.

What do I need as far as memberships etc.? I know what I need for this club, but do I need to be a member of a Bullseye Group of some sort as I do for Benchrest rifle? I notice people showing their NRA Level, where do I find information on how I work toward getting a rating? 

For my skeet shooting , I joined the National Skeet Shooting Association decades ago and was "Unclasssified" until I shot my first 300 registered targets.  

Just want to do this right. 

Thanks, Bob

I’d join the org that sanctions the league which is most likely NRA.  Your scores are tracked by your membership number.  Your rating is based on scores shot, and for the first match you must shoot as a “Master Unclassified”.  After that your previous score history can be used to get a temporary classification until you get the requisite shots reported to the NRA.  Leagues operate slightly differently so you may not get the scores reported until the league is complete.  But the league director can guide you..

I joined a 900 league that shoots once a month for six months, and then reports to the NRA at the end. But the CT State Championships are in the middle of those six months. So I have the temporary NRA logbook, and will slot me as an Expert for the states.