Able to choose month in calendar or advance ahead?

Hi, we have installed your plugin for our site, http://www.outofthegardenproject.org. My programmer and I are having major issues getting the calendar to provide a choice to pick a different month or advance from month to month. It will only display the current month (in this case, June). This seems like such a simple navigational issue. Are we missing something or is this a hole in the plugin? Please help!! I am not a programmer and am just trying to help this non profit with a calendaring solution.

http://wordpress.org/extend/plugins/events-manager/