A lot of my followers (and a lot of the talented artists I follow) are pretty young! And there are some time old trends in online behavior that I frequently observe (and participated in myself when I was young and hip).
There are some things that you just won't fully learn until you've experienced them enough times for yourself, but there's one online posting trend that I'd really like to caution my friends and followers about. (and honestly, this applies in real life, too).
Don't talk shit about people.
Don't do it. And if you gotta do it, don't do it in a public sphere where everyone can see it. Aside from it being a poor character trait, that sort of thing can run you right out of the communities you would otherwise enjoy. It makes coming online stressful. It sits heavy.
I understand having really intense and frustrating feelings that you don't know what to do with, but believe me--if you have to blow steam about someone, don't do it in an archivable, public