Everything seems to work, but when I try to join a server I get an error When I try to join either one on the zombiemold servers I get this:
I don't know what to do.
This message means that you are using the wrong version of minecraft. "Outdated server" means that the server is using an older version of Minecraft than you are.
The best way to find out what version they're using is to contact the server administrators, or go to their website if they have one.
For the server on the top, it shows the version of spigot you need in red, and sometimes the launcher will also show the version of Minecraft that you need in that manner.