Flying to Beijing and the cruising from Tianjin to Shanghai and Hong Kong.

Flying to Beijing and staying there for sight seeing as long as Free entry allows. Travel to Tianjin to join cruise ship. 5 days later will be in Shanghai from 7 am to 6 pm and 3 days later in Hong Kong from 8 am to 7 pm the following night.

Can the policy entry be used for this. Cruise is booked but not flights at this time. Waiting for response to this question as to how long I can stay in Beijing and can I also us Visa Free entry for Shanghai and Hong Kong.

Thanking you in advance for your help.