When will the finals tickets go on sale and when will we hear where the finals is played

I am an American and me and my friends have attended worlds almost every year. We are looking to got o china this year to support NA in the finals if we make it or just cheer for an exciting finish to the league of legends competitive season. But its almost a month away and we haven't heard anything about tickets for the finals. Nor have we heard where they will be. When will league tell us. we need to book flights immediately.