Need help quick....!

Hey, ok well I used to be great at gfx, and I decided to start again. I use GIMP, but I cant seem to find out how to do something. I need to get new brushes, and I know that you must go to Toolbox/File/application.. ect. I know that, however THERE IS NO FILE!!! I CANT FIND IT!!!!!! I AM USING A MAC!! SO PLEASE DONT GIVE ME TUTS FOR WINDOWS!!!!

Here is a picture of what Im looking at:
http://img204.imageshack.us/my.php?image=picture1vt7.png
Why does it not say file anywhere? Please help me.

I also duno why this picture is coming out so small. But please help.