A couple of things that helped me when I got into mtg: check out some tier 1-3 decks (pro tour winners, GP winners, brews from pros., etc.) It will help you get familiar with deck building strategy, i.e. Mana curve, synergy, interaction with opponent, win condition, all around having a plan that has power and consistency. There are a lot of good places online that have free content that will help you get better. I look at the
channel fireball website almost everyday. You can find good stuff here as well. As far as your g/b goes, it does need some tuning, you might find it to be a bit clunky. However, I do really like
winding constrictor decks, and looking at a couple g/b deck lists will give you a lot of info on how to tune this deck. Deckstats has a slight learning curve, try organizing your deck list by card type. It will help you and others be able to see your plan clearly. I hope all of this will help. Welcome to magic, it's the greatest game ever made.