Here's what we know:

In 2017 someone claiming to have "Q level Clearance" begin posting anonymously on 4chan. Since then there has been drama and now he posts on 8kun, but it's the same concept. All of those posts are collected on sites like Qmap.pub

The contents of those posts have outlined the existence of a deep state, and hints towards dark and terrible things. They also outline the behind the scenes efforts been made by patriots to disrupt and destroy their control.

Many people around the world are convinced of Q's legitimacy and use the posts as launching points for their own research and presenting their own findings and discussion. There are also a series of connections that have been made between Q posts and known information, or later revealed information which act as a sort of confirmation of Q's legitimacy.

One of the biggest sticking points with Q is are what his detractors call "failed predictions". Obviously if Q is legit and we are the good guys reading it, the bad guys are too - so sometimes you might want to put out some disinfo purposefully. To me, the proofs far outweigh the "fails".

One of the biggest things to remember as you get into it is to distinguish between actual Q drops and speculation by enthusiastic supporters. For example, there are a few users who love gemmatria and they're always adding up letters and discovering meanings. They might be onto something, but you don't want to get get their claims mixed up with Q.

That's a very broad overview of Q rather than Q's claims. Happy to answer any questions.