As a small business owner I can tell you YES you need insurance! Both for liability, someone hurts themselves on your property, and for your supplies, poles, floor, pads, etc. Different companies specialize in different businesses. If there are any locally owned dance shops or gymnastic studios close to you I suggest you call the owner and ask them. Insurance isn’t terribly expensive I suggest getting as much as you can afford.
Think about all the ifs like, what if your home floods? Or someone trips in your driveway on the way out? I would also suggest making an LLC for your business to protect yourself. It limits your liability so if the worst does happen and you get sued they can’t take your home, car, future earnings, etc.