Why you wanna learn Kung-Fu??? Kisi ladki ke bhai se panga le liyaa hai kyaa ?
Anyway... Somethings (actually anything

) can't be learned from reading books. Better find a trainer... and before that increase your stamina... do the following workout 4 atleast 4 months..
1.) Morning :- 3 KMs Walk and 1 KMs of running. (I do)
2.) Morning :- 20 Push-ups each day and increase them to 40 by last month. (I dont do.

)
3.) Morning :- Do half hour Swimming each day if possible. (I do)
4.) In day :- Never use Lifts, use Stairs (I do.

but there is a big reason.

)
5.) In night :- Do simple Yog-aasans for half hour.
Simple stuff. But will improve your stamina surely.
Note :- (Do all this while wearing special clothings which must weight more then 35 pounds

)