Honestly, I learned all of these from browsing cgl, instagram, and tumblr.
What I do is start my searches with generic terms, such as harajuku, kawaii, jfashion, etc.
Then I narrow my searches to the type of look I want. So if I want to learn about girly looks - gyau, romantic, sweet. If I want cuter looks - pastel, soft, cream... Kinda like searching with an aesthetic in mind.
Then I just link-hop and click on all the photos, links to stores, and that leads to more defining terms/ people who are more expert at the style to define it
Is this what you were wondering?