China requires US citizens to apply for a chinese visa in order for an extended stay. There is no visa issued at travel time so it's critical that if you RSVP to start applying for a Chinese visa asap. You can find more info here: http://us.china-embassy.gov.cn/eng/lsfw/zj/qz2021/202206/t20220614_10702581.htm
Air travel to China is still limited at the moment so airfare is relatively expensive. We're expecting more flights to become available as China continues to open up. We recommend looking for tickets in the near future (maybe in July)