@agameseo the blank cart and checkout pages are not BuddyPress issues, only the member, register, and activate pages are. Was your shop working before you activated BP? If not, then I suggest you contact the theme author.
Re BP pages returning blank, does your theme’s page.php have the_title and the_content tags within the WP loop? If not, then you’ll have to customize your buddypress.php to have those tags within the WP loop or hire the theme author/developer to help you customize this premium theme which we have no access to.
