This is a 粉丝 run page. Markiplier himself (or any of his associates) do not have any correlation to this page 或者 Fanpop.
As for your question, I couldn't find anything about a meet and greet - it's still a 月 away. I'm sure 更多 information will come out as the 日期 gets closer.
Other than that, I hope 你 have fun at the show. :)