Yes, there are multiple flights from Abu Dhabi International to Huanghua International for under AED 4200. The cheapest flight booked recently is on China Eastern for just AED 4138, but on average you can expect to pay AED 4980.
There are no direct flights from Abu Dhabi International to Huanghua International, but Cheapflights can provide you with all the information you need to find the fastest route with the fewest stops.
When travelling, it's generally smart to pack in preparation for rain or any other conditions that may arise. The rainfall in Abu Dhabi is roughly less than Changsha. You can assume this to be the case over the next 0 days.
Expect the weather to be around 43 °C on average in August. As the temperature peaks, try to get your plans done early, as flight price and availability will have an impact on your travels. The climate in Changsha is generally colder than in Abu Dhabi.