The people you meet are simply whoever happens to be online. In practice that means China and its East Asia neighbours — Mongolia and Japan among them — mixed in with strangers from every other continent, which is a fast way to lose an hour.
Mandarin is the everyday language in China, and a few words of it change the mood of a chat immediately. Beyond that, simple English and a shared sense of humour usually carry the rest.
Time zones do most of the work in deciding who is awake. China runs on UTC+8, so its 8pm is 1pm in Berlin and 5:30pm in Mumbai, and evenings are when conversations stretch past the first question.
There is no charge. Every chat mode works the same for visitors from China as for anyone else in East Asia, and none of them sit behind a paywall.
Nothing beyond the 18+ confirmation. Video and audio travel straight between the two browsers over WebRTC — the same in China as anywhere else in East Asia — so there is no profile to create and no chat history attached to you.
Chats usually open in Mandarin. A greeting in it changes the mood immediately, and after that most people are happy to work through the gaps in plain English.
Late evening tends to work best. China sits at UTC+8, so 8pm there is 1pm on a Berlin clock and 5:30pm on a Mumbai one — chats in that window usually run past the first question.