Vietnamese Passport holder eligibility

I'd like to confirm my eligibility status:

Vietnamese Passport holder, traveling from Japan - Yangtai - Shanghai - Thailand. I will arrive and Yangtai and leave Shanghai on the same day, within 24 hours of arrival. But I will be on one domestic flight (Yangtai-Shanghai).

Does this mean I do not need to apply for anything in advance?
I just need to fill out some forms in the airport border counter at Yangtai?

Thank you for your answer.