Hi,
When you start out with Mobile Joomla MJ it takes a while to get the hang of it as it does not work in quite the same was as Joomla.
Incorrect usage of Mobile Joomla is an error message that usually means that the template has been assigned to a page. The templates should not be assigned; you should let MJ choose them by itself. The only place you should assign them is
Components > Mobile Joomla > Settings > and then the tabs for Smartphone iPhone WAP imode
Template name. Even then it is rare to change them.
If you can't find where the problem is, then uninstall it and reinstall and don't change anything and you should be able to see it working. I'm suggesting this because you have only just installed it.