No, you will get into shape as you train. We have a series of exercises that you will learn as you progress through the ranking system which will enable you to perform the self defense techniques.
No, you are not too old to begin martial arts training. We have/had students start from adolecense through their 50's and older.
Three 1 hour classes are week are recommended.
Typically, a student can achieve their black belt within 2 1/2 to 3 years with dedicated and consistent training. (It may take younger children between 5-6 years.)