Believe it or not, the notions of free will and destiny are not mutually exclusive.
Predestination is the universal framework of limits (based on natural physical laws) placed upon us.
Free will is our infinite ability to make choices within that framework.
Because the universal scale is so great—and most of it constitutes an undiscovered frontier—our choices are only limited by our knowledge, our abilities, and out imagination.
To put it simply, the world is such a huge playground sandbox that we will never run out of sand or reach the faraway safety fence of destiny.
So go out there and play!