How do I make the JV boys basketball team next year as a junior?

Im trying out for Junior Varsity basketball in 11th grade and I am skinny but I dont run very well because of ashtma. Im also very weak. How can I improve my stamina and endurance to run in basketball and my arm and leg strength?How do I make the JV boys basketball team next year as a junior?
Try running up stairs and running a few miles each day.

kuryakyn