The human mind is an amazing thing! If you learn two or three lines of the Athanasian Creed a week, you can memorize the whole thing within 15 weeks!
To be honest, this Athanasian Creed Memorization Guide follows another example, building in review periods, for a total of 20 weeks. Still, if you start mid-August, your whole family can finish by Christmas!
The text of the Athanasian Creed is not included. However, you can find the creed in the front of hymnals and in every version of the Book of Concord! Including the online version at bookofconcord.org.