There are some buttons in the top left corner of the editor. One button shows a disk and a red arrow pointing to it. This is the button for saving. In the saving screen you can give your map a filename and an editing-password (so that nobody else can edit your maps). To save, click the tick in the bottom right corner of the saving screen.

And please give your threads more-saying titles, not "question about ...". To show that there's a question, you can add a question mark at the end of the title.
I did this in this thread for you.