One you decide to join GT as a full subscriber, before jumping in to the Blues lessons, take the time to go through courses called the Guitar Fundamentals 1 and 2.
These are made to really give you a basis to grow from. I've been playing for a good many years but was self taught. Going through the F1 and F2 courses builds that basis (or in my case, fills in blanks).
Good luck and glad to see you at GT!