Many people think of yoga as stretching for fitness. What is really on the mat is preparation for meditation. It is working the body and mind to better settle into quiet. This quiet time helps to improve our conscious contact with a Higher Power.
No matter if your taking yoga class at a studio or practicing in the home allow yourself that extra time when finished to sit quietly afterwards. If coming from a yoga studio try to keep talking to a minimum or none until you can get to your meditation. You may need to quietly leave class when finished and find your quiet space either in your home or a special space outside. Some teachers leave time for a deep meditation period after class and that may be all you need.
Focus on the breath especially when distracted. Distraction is normal in meditation. Simply bring your concentration back to your breath. Breathe deeply all the way down to the belly, expanding it like your belly is a balloon on your inhalations. Keep your mouth closed and breath through the nose only.
Most importantly do not judge your practice. If you have just started or have been doing this for years it is all good. One baby step at a time. One inhalation at a time. One experience at a time. Just keep practicing one day at a time.