I came across this interesting video about the My Little Pony fandom (the Bronys). It is by Jenny Nicholson, who has a great long-form YouTube channel, and who was an active part of the Brony fandom, so she is a great guide.
It is not a fandom I know much about, so this was a fascinating introduction to me. What I appreciated is that Jenny Nicholson is non-judgmental but is also not afraid of pointing out negative things about the fandom.