First time playing on Voobly and I can get into the chat room but not click "Join Game". I ran the diagnostics check and it said everything was successful. I've downloaded the recent patch and the compatibility patch. I can host my own game though

hi
so you have the steam version of the game?: https://support.voobly.com/display/vkb/KB1054+Clean+installation+of+Aoe2HD+with+compatibility+patch
when you say "cannt click" is the button greyed out or you click and nothing happens?
is the game/voobly allowed through your pc firewall and anti-virus?

I have the same issue, i have the steam version and when i click join game i get sent an empty message with a red X and nothing happens

That seems like a patch mismatch issue or you may not have had the patch correctly installed. Also note that the steam version by itself is unplayable here and you need to have the compatibility patch installed.

Please follow the steps mentioned here to perform a clean installation of the Voobly client
http://support.voobly.com/display/vkb/KB1053+Clean+installation+of+Voobly+client

Then follow the steps mentioned here to perform a clean installation of the game:
http://support.voobly.com/display/vkb/KB1054+Clean+installation+of+Aoe2HD+with+compatibility+patch