The best thing to do is find a teacher who really cares about your goals and your progress. You don't want someone who just "goes through the motions" of teaching, but only sees you in terms of the money your paying.

Other than that, focus and goal setting is key. Why do you want to play guitar? What is your ultimate aspiration? Once you figure THAT out, work backwards, trying to figure out the steps towards that goal. A good teacher can help you with that also.

Remember, always stay focused on the goal.

Take care.