18 nights in China (Shanghai to Beijing) in August with a 20-month-old. Need itinerary advice!

Hi everyone!

I’m planning my first trip to China for 18 nights next August. We are flying into Shanghai and departing from Beijing.

We will be traveling with our 20-month-old daughter, so our top priority is keeping a slow and manageable pace. Last year, we traveled through Japan in August when she was 8 months old. We know how intense the heat and humidity can be, so we survived by keeping our itinerary light. We want to follow a similar "slow travel" philosophy for China.

Note: If possible, we would love to spend a few days at a beach near Beijing to cool down and let our daughter play before heading to the capital.

We appreciate any advice from parents who have traveled to China with young kids! Thanks