Im still having lack of skill toward portrait and fashion photography editing and retouching. I did try to learn by myself by watching videos from Youtube but I faced the limitation. I I wonder if there is a course or class to study and learn Photoshop in detail in NY area? Any advice?

If you are looking to improve your photoshop skills and knowledge (tools to use: wich, how, when, and why) internet is best place for you. You may want to try https://phlearn.com one can learn quite a lot even form the free tutorials they offer

If you need more knowledge regarding shading and color grading you may find drawing course more effective and chiper than photoshop classes especially if you are using any touch device to work on your photos. If you know any proffesional MUA they should be able to give you some pointers, to be honest half decent high school art teacher should do.
To be even more hardcore you may visit public library and find some amazing books about teory of shading and coloring.