what is "You're off to great places. Today is your day! Your mountain is waiting. So get on your way!" means

It means that you're going to move on from your current situation of life. "Your off to great places" means the choices you make each day no matter how small could or will change how your life will continue. "Your mountain is waiting" means the choices in the future are already set for you; also known as "fate". "So get your way!" Means to start your actions now.