First, study the Betsy Ross Site.
Betsy Ross Site

Then, sew an American flag.
Use the design of our present flag or any of our past flags.
(If you choose to create a flag according to our current flag design, you may use this flag, if you wish, should you decide to do the Justice project, J305, Flag Ettiquette.)

The following links will help you in your flag construction:
About: Sewing (Make an American Flag)
The Betsy Ross Site (Make a Five-Point Star)