Recognize what is going on and gently bring your focus back to the breath. This small act of not judging yourself during your sitting, will expand into your life when your eyes are open and you actually judge yourself less. So bring your focus back to the breath.
If you'd like to meditate but are having trouble getting started, using guided meditations can be a great way to explore different types of meditation and to kickstart your meditation practice. You might find that certain approaches resonate with you while others don't.
The short answer is yes. Yes, yes, and yes. And in case that wasn't clear, yes. The long answer is: Contrary to popular belief, meditation is not just a health trend like kale smoothies and spin class (not that there's anything wrong with those things).