Welcome to the site. I see your from Brooklyn. We have a few members from the Brooklyn, Staten Island area.
Im glad you took the time to check out the beginners clinic. Here is a page on Brooklyn. The piers have GPS (Global sattelite positioning)coordinates you might have heard of some of them. These locations are fished by the locals in Brooklyn for stripers. https://www.stripers247.com/Brooklyn.htm
It is by no means comprehensive. Jamaica Bay, the east river and for that matter anywhere there is water there is the potential for stripers. Just some locations are fishier than other. Keep reading different posts from this area, New York, New Jersey, Long Island and Ct. to get a picture of bait used and methods.
There are party boats out of sheepshead bay at night that supply the pole, reels and bait for about 40 bucks a head. Right now most are out blue fishing, but come september more will start fishing for half night striper runs. Sometimes it is good to go on a party boat and watch how the bait is rigged and how the other guys are catching. It can be a lot of fun. Of course you have to deal with crowds and possibly tangling lines.
Check out some of the feedback posts to some of the other Rookie fishermen. And get out there and fish. Bring your freshwater skills to the saltwater. You can even use the same gear to get started off of a jetty.
You will have to get bigger and stronger equipment if you want to bring in a monster fromn the beach. But light action tackle can be a lot of fun also. Using poppers and plugs. Make sure you rinse the saltwater off your gear when your done. And like Charlie said talk to the local bait shop guys.