To be guilty of a crime, generally, the State needs to prove beyond a reasonable doubt mens rea (evil intent) and actus rea (evil action). Here, it seems like you did not have an evil intent based on these limited facts. Be careful on the internet. Good luck.
The above is general information only and is not legal advice. The information provided does not form an attorney-client relationship, and should not be relied upon to take or refrain from taking any action. I am not your attorney until we sign a retainer agreement.
It is difficult to answer questions like this because generally there is more to the story than is being presented initially. The cases of solicitation of a minor for sexual purposes I have seen have generally culminated in a personal meeting, or an attempt at a personal meeting, that follows up on prior communications of a sexual nature. Police do often pose as underage persons interested in sex, online, in order to catch people interested in sex with underage persons. More important than worrying about what might happen (beyond your control), are 1) consider avoiding the conduct that led to this trouble, in the future; 2) know what to do if contacted by police - assert you rights to silence and an attorney during questioning; and 3) be prepared for searches of everything you own and are associated with. This sounds easier than it is to do - but these are vitally important to protect yourself from police methods and errors. Also, avoid posting details online. You may want to follow up with an in-person consultation with a criminal defense lawyer.