Try to focus on your breath. Notice if any thoughts come up (and this is completely normal) let them go and focus back on your breath. With time and practice this will become easier.
The goal is to find stillness. But if you have to move and readjust that is perfectly fine. The meditation above will guide you through finding stillness.
The beautiful thing about meditation is that there is no wrong or right way. With time, practice and patience, you might start to notice the subtle changes and improvements in your life.