To help you maintain the stillness during the meditation, a comfortable position is essential. Many people mistakenly think that meditation is only possible sitting in a specific pose, such as crossed-legged or in lotus. However, if you never sat like this before, this pose won’t be comfortable, or even achievable and your practice will suffer.
You should find a position, that will let you keep your spine erect during the meditation without strain. This is possible when your knees are below your hip level, for which you need to have open hips, flexible enough for the knees to reach the floor if you sit cross-legged or in lotus. When this is not possible for you, but you still want to sit this way, place a few cushions under your sit, to raise the hip level. This will bring immediate comfort and will correct your spine position.
Otherwise, sit on a chair with feet reaching the floor comfortably. Too high chair and inability to place your legs on the floor will create tension at the back of your legs. The too low chair will make the position of your knees higher than hips, and your lower spine will curve outwards, losing its straight line needed for mediation.
When you know how to prepare to meditate, you eliminate the distractions and enjoy the experience more.