training program completion certificate

I am a college student looking to become a CNA, then an LPN or RN after i complete my CNA. I found out that i don't even need to take classes at my local community college, some options i found out were that i could go to a local nursing home and they will pay for classes in exchange for working for them. The classes they pay for are for the training program completion certificate. I was wondering if you even needed to do the training program completion certificate, or if i could just study on my own by various things like books, the internet and other various study materials. When i am ready, would i have to go to a testing site in my state (Washington) without taking those classes for the training program completion certificate. Or is it required that i take those classes? So lost and confused. Thanks!