Simply sitting and watching your breath if you are beginner will calm your mind but progress will be slow.
If you are already into taiji quan and your qi is circulating then meditation is easy to pick up and will compliment your taiji quan ( considered also as meditation in movement). If your qi flow is good, simply sit comfortably, relax , free up all thoughts. Watch your breathe and you can also keep your awareness at your dan dien area. The qi will flow on its own.
If your qi points are still blocked, then it si best to find a master that can help you to open these qi points.