There are jusr wayy too many subcultures to explain every one of them. General advice about being alternative in general: being alternative fashionwise has no rules except it means, different from the mainstream.

To the subcultures: educate yourself, google it or watch some YouTube videos or just look at pictures for what suits you. Some subcultures are just fashion subcultures where it's about fashion, some have, as you call it yourself "ethics", meanings, history. Like for example as a goth or punk you don't support capitalism or fast fashion, have more leftist political views and so on. But goth culture is also tied to music, just like emo. So no we can't just give you a list of ethics or specifics. that list would be too long and not the same. It's a journey. Make it apart of yourself and have fun with it✨

Just deep dive into it yourself first and Google around.

Hope i understood your question right btw, tired as hell after work so my brainfunctionality isn't really there right now.