a group of people with nothing better to do than bitch about people who like things, doesnt matter what they like, as long as you like something they hate you. My advice: Pull the stick out of your ass

A term often used poorly by people.
Conformity and nonconformity is a spectrum that one exists on. Each have their ups and downs and neither absolute is possible for normal people.

A conformist tends to go along with society's rules more often than most, and tends to do so uncritically. Everyone who is not a psychopath conforms a little. And part of having good manners, morals, and behaviors is conforming to rules set down by people who are long dead and built the society you live in (and probably knew better than you).
A non-conformist is more elusive, but it simply is someone who is an individualist and values their own agency. As with conformist, it's not an absolute for normal people. And many non-conformists are wrong because going against the grain has an inherent risk, especially since most people don't know better. Otherwise everyone would do it
There are some paradoxical overlaps. For example, a non-conformist playing nice to appease people is conforming in a sense but is a practical cost of doing business in the real world.

Ultimately it comes down to how often you exercise control over your own life when you can practically do so. And anyone who uses music, or clothes as an example of their nonconformity is kind of a retard.

Somebody who hates baby kittens, thinks the earth is flat, thinks vaccines cause autism, posits that climate change isn't real, that the moon landing was just a hoax, and every other nutty conspiracy theory you can think of.

Many people would think non-conformists are simply people who like unpopular stuff. But realistically the "unpopular" stuff is still rather popular to a certain degree (e.g. classical music).

The REAL non-conformists are those that actually like or support something that literally nobody would like or support. And those people are typically conspiracy nutjobs or psychopaths.

A non conformist is someone who does not think, act, or behave in a way that could be classified as "normal" in their own social environment. Everyone can be classified as a "non-conformist" in some way because conforming is really someones perception of what is normal or acceptable. The more people who think, act or behave a certain way, the more "those" people feel empowered to tell you "their" way is "Normal". And since normal cannot be quantified, we each have to decide for ourselves to what degree we want to conform.

A non-conformist is someone so obsessed with being different that they go to great lengths to avoid social norms; typically, you can identify them in a shopping mall because they all dress alike, listen to the same non-conformist music, and read the same non-conformist literature.

As it happens, it is also non-conformist to have any sense of self-awareness or irony beyond surface-level sarcasm and "snark".