It makes me very sad that a 13 year old is even thinking about creating adult content. It makes me sad that adults think about making such degenerate things.
ngmi
You seem like a well-meaning kid, so I'm going to not sugarcoat it. IMO it's better to have this stuff presented in a sanitized environment.
R34 means "rule 34." Basically, it's slang for anything that's sexual content of something, most typically some existing IP. Something like adult-oriented content of two characters from some cartoon.
(Protip: "Adult-oriented" is most often read as a clean way to say "sexual content." If you're not doing that, it's better to just explicitly say what you think is not child-friendly (i.e. graphic violence, vulgar language, traumatic themes, etc). This also has the side-benefit of warning users who might be sensitive to specific kinds of content.)
Furry has a lot of definitions, depending on how vulgar someone wants to paint it, but the most broad definition is "anything to do with humanized animal characters." In that sense, it can range from anything like Sonic the Hedgehog or Zootopia (stylized human/animal mixes) to Warrior Cats or Redwall (animals that just act like humans), but typically a lot of people take it to specifically mean a more humanized style found in a lot of internet subcultures (often animals with human bodies), or someone deep into these subcultures.
So combining the two, it's basically someone who makes really crappy adult-oriented art of something like the Alpha and Omega series (link is just a novel cover for reference).
Anyway, people gave you answers for Itch's policy, but if you want to make something in the meantime, it doesn't really take THAT much to do, but you should start with figuring out what specifically you want to do.
its more of im curious on what im allowed to curate im not saying i want to do this im giving an example of the most extreme, if this wording makes sence. also im not a very sexualm person infact i very idk about that stuff im fine with people doing that stuff but i am not interested in that at all (1. i dont want kids, 2 i am probly way to focused on making stories, 3 im just not into sex, im honestly not) also i want to create stories of creatures lives, i want to explore morality as not real and just as a consept(no good vs evil) also other consepts as well but im using this one as an example)
Not with that attitude.
Just do it. Make what you want. Nobody gives a shit who you are or how old you are. What they will care is if you make something worthwhile or not. If you want to make something, make something. Don't spend an entire sentence wasting people's time about how you prefer to misspell a word. The only reason anyone would even know you are 13 is because you made a post about it (and also because your mode of speech betrays that just a bit). Just shut up and make something. If it's stupid, you'll find out. If it's worthwhile, the community will let you know. Whether you're 13, or interested in sex, or have a good relationship with your mom, or like to misspell words is completely meaningless compared to what you create.
Just make something. I'm not trying to be mean, I'm trying to give you some motivation. Don't bother what people say you can create. That's not art. As soon as you care that somebody tells you that you aren't allowed to make something, you are no longer an artist. An artist creates because they have to... because they know no other way to exist. An artist will find a way to create even if no one will allow them. Hell, if you need a hand, let me know. If you are actually creating something of value and not just, as most of the people who responded seem to think based on what you've written, some meaningless juvenile crap, then it doesn't matter how old you are... what matters is that art deserves to get made.
So before you concern yourself with whether or not you can or should make something based on how old you are, the question should be this... does what you want to make deserve to get made? If so, then you would be OBLIGATED to make it, even if you were only 7. Just don't confuse what your juvenile mind thinks deserves to get made with what actually is worthwhile. Most people your age think they have a clear understanding of the universe, but that's only because everyone at every stage of life feels like what they think is the only thing that is correct. This is related to what's known as the Dunning-Kruger effect. People think that what they know is the height of knowledge because they don't actually know how much there actually is to know. Don't be upset if you pour your heart and soul into some game, call it "adult concepts," and have adults snub it. If you are 13 years old, you will probably have a much better time making things that are meant to show your own point of view from your perspective rather than trying to make something you think will be deep for everyone. An adult would enjoy your game more if they knew they were spending some time looking at things from your perspective, rather than having you say "I'm thirteen and I think this is deep," because that will result, most likely, in scorn before people even bother to play the game... they simply will not believe that what you think is deep is worth their time.
It's all about perspective.