I'm not going to lie to you: there are some pretty awful things that happen in fandoms and the community surrounding it. Someone could literally come across anything while searching through the comments of a piece of art for said fandom or someone's comments. People can be mean and be hiding behind a screen enables people to be mean and to make fandoms "cringey" or "toxic" as people have put it before.
No fandom is safe from this either. From Fire Emblem to Harry Potter, there are parts of the fandom that you just don't want to be a part of or hear about. However, there are some good parts of fandom including the people who care for one another, making memories that you will never forget and the encouragement that comes from being in a fandom.
This is not a recruitment for a certain fandom, but merely a way to tell you of all of the good parts of fandom and the people who truly want to see others succeed.
I have been a part of the fandom and the communities that surround it for many years: since I was a young high schooler just getting to know what it was exactly. Since I was so young, I had not really seen what this supposed toxic side of fandom was. However, now that I am older, I have seen and heard some things that I would rather not have experienced.
Those experiences have made me appreciate the people who make the world and the fandoms a better place. An example that I can think of is the people who stream on Twitch. It's true that not all people will be like how I describe, but you will find that there will be a fair amount. I follow a couple of creative streamers (cosplay and the sort) and they are some of the nicest people that I have met.
They welcome everyone with open arms and are willing to answer most questions about their craft or how long they have been involved in the community. The streamers I follow also share common interests, so we are able to make jokes about it and get each other's sense of humor.
Meeting these cosplayers and gamers at conventions is one of the best parts. Since you already know a bit about each other from the fandoms that you have in common, you're able to make conversation without it becoming awkward or embarrassing. This goes for most cosplayers or people who are a part of fandom as well: most people will be open to general conversation about the fandom that is civilized and polite.
Once in a while, you get the people who are considered to be "trolls" and try to be mean for the sake of being mean. However, I have found that the number of people who actually enjoy a presence that is kind and welcoming outnumber the people who are there to be mean.
Fandom and cosplay have a lot in common in terms of community. Surrounding yourself with the right people can also help to make your fandom or cosplay experience a good one. Not all of the fandoms are bad and some of the best parts of fandom are the people who make it great.