I have installed yesterday this CMS look nice and promising. I have tried it and wondering how can i activate rating and paypal plugin I have already checked the check box in plugin section but it has no effect in the front end maybe i am missing something. Second it uses the site name for the home button can I all change the Home button text without changing the site name if yes then where i need to go to change that.

Both rating and paypal are zenphoto plugins. So two things are needed to use them. First, you have to enable them in the admin/plugins tab. Then the theme you are using has to support them. Check the documentation on the plugins for how they are used in a theme. Generally there is a function call defined by the plugin that has to be inserted into your theme where you want the feature to show.