When I was a first year apprentice an old master plumber told all of us in class, "You all wont know a thing and will cost your boss money until your third year. Then and only then will the light come on and you wont be so damn ignorant about plumbing." I was a bit put off by his statement to say the least. However, his words were prophetic. Taking a 6 month or 1 year course does not a plumber make. My apprenticeship was 5 years of school and OJT. Sure, I could solder up copper and put CPVC together long before then, but I still didnt know enough to be a plumber. If you're ambitious go for it, but in the long run you might be better served by hiring a licensed professional who has years, not just months, of experience.
Whichever way you decide to proceed, I bid you lots of luck.