Put the Glazed Builder module in sites/all/modules.
Go to Admin > Modules and enable the Glazed Builder module, the Glazed Builder Block Type and the Glazed Drag and Drop Node Type modules. This will make the Glazed Builder available for use, and create drag-and-drop block and node content types. (The modules have a number of dependencies which you should review and, if necessary, meet by downloading and installing the relevant modules from Drupal.org).
You will now be able to create drag-and-drop node and blocks.
To enable the builder on existing fields you have to set the field formatter to Glazed Builder. For example: on a node type with machine name page you can change the Formatter at admin/structure/types/manage/page/display.
If you don't use Bootstrap 3 in your theme:
Go to the Glazed Builder Settings Form at admin/config/content/glazed_builder.