VJB is one of the highest risk/reward programs ever... thats on top of the fact that pretty much any one of those "get mega hops in 2 months!" programs will destroy your knees if you are still under developed (i.e. 15 years old). I SUGGEST that you wait until your at LEAST 21, but since you wont then at least wait until you are 18-19. I know it seems forever away but its the general consensus your going to hear on this board anyways (this has been thouroughly debated) that these programs and anything special like this are a BAD idea until you are fully developed.
In an attempt to placate you I will blow some sunshine up your ass now...
1) As a 5'10" freshman grabbing rim right now you will prolly dunk by the time your a senior. I couldnt dunk until I was a junior and I wasnt grabbing rim until that same year. I just let my body develop and since your already wired for hops it will only get better.
2) You dont need anymore sunshine. Dont ask messageboard idiots what to do, go out and just ball/work/fly ect.