Actually, you cannot publish anything. Not on itch as a 13yo, you can't.
"Users must be 13 or older. Publishers must be at least 18 or have the legal right to enter into this agreement."
"If you register an account to sell, distribute, or publish games or other content on itch.io, you agree to be bound to the terms of this Agreement as a platform publisher (“Publisher”). Publishers affirm that they are either more than 18 years of age, or possess legal parental or guardian consent, and are fully able and competent to enter into the terms, conditions, obligations, affirmations, representations and warranties set forth in this Agreement."
If I read that correctly, you might publish with consent of your parents. That your parents know what you draw is not the same as them allowing you to be a publisher.
What type of content you can publish would be dependent on the legality. If you can legally view your own content (yes, that is as stupid as it sounds), I do not see any problems. Itch has not really any restrictions, other than the legal stuff. If your comic book violence and "adult" stuff is legal for you, and your parents allow you to be exposed on the internet, my opinion as one of these strangers you should not talk to, is, go for it.
And my 2 cents about the reasoning behind this is really that thing with the exposure. If you publish, you might get contact to people that will be not very nice to you. Especially, if you flaunt your age. They might not believe you, or try to goad you. And to be honest, your post reads like a troll post.