While throwing a ball for my dog the right side of my back clicked and i now have a numb right leg,do i need to get urgent help?

It's possible that you sustained a herniated intervertebral disc in your lower back. Unless you develop definite muscle weakness as well, I wouldn't consider this an emergency but you should see your physician, a neurologist, a neurosurgeon or an orthopedic specialist for evaluation and advice as soon as you can to be sure. In the meantime continue to be up& about but rest your back.