You will shortly be deluged with helpful suggestions. I will only add that this need for training depends somewhat on your existing familiarity with tools and reading plans and having a "sense" of the material you're working with and what's smart and what's possible. If you're at all nervous, by all means do an EAA or other metal building class, but if you've got experience and confidence you might pick up enough by finding another builder (best if they're build is still in progress so you can see behind the curtain) and spending time in their shop.
You're gonna love this place.
Clay Cook