Which is more fun to travel to Suzhou or Qingdao in July?

Depends on what style you like. Suzhou is a standard scenery in the south of the Yangtze River, with a taste of classical beauty. It is better to enjoy the gardens. Qingdao is a beautiful coastal city, famous for seeing the sea and the marine world. If you go in July, both places may be a little hot, but they are both good choices.

Have a nice trip.