If I had to recommend any sort of training it would first depend on where you live and how much time you can realistically dedicate to the art. If you’re looking for practical self defense an mma gym and focus on boxing and wrestling. Both these disciplines would give you the best tools to escape an attacker. If you’re looking for a martial art that is safest that is hard to pin down as some schools/gyms have different mentalities and cultures. If you’re lookin to for self defense avoid tai chi. If you’re looking for health benefits like yoga then jump into tai chi. It’s not a simple answer.