This is a standard text-edit window.

Click here to select a layer number to be affected by the Current frame window.  Using Shift, you can add & remove items from the affected list.

Click here to choose the displayed special pen.  Option-click to load the special pen from the clipboard.

Click here to choose the displayed pen shape and size.  Option-click to edit the pen.

This is the user-defined toolbox.  Command-drag any tool, color, or pattern into or out of this toolbox.  To use something in this toolbox, just click on it.