Your sentence is slightly incorrect, I expect it should be "I'm sure there is someone out there that will click with you". Click in this case means like two Lego bricks connecting together, they make a 'click' sound. A person who clicks with you is a person that is very compatible, for example you have the same interests, or you are attracted to each other. It means a person that just naturally and easily connects with you.
Another example would be, "I studied Japanese for 5 years and I couldn't understand it, but then I read a book about grammar and it just clicked." This means the same kind of thing, like a Lego brick that suddenly fits into place, I suddenly understood Japanese because it clicked.