When you drag a clip to the right hand column, you have put it in the first group of your first library.
You should now give a name to the library and group
Click the Name Group and Name Library buttons. In the dialog that opens, you can add highlighting as well as enter the group and library names.
To change libraries, click on the library name
To change groups, you can either, click on the group name or right click in the column header which now shows the name of the current group.
