Hello huyen_danh
Welcome to the community forums.
This community forum is a good platform to ask the questions and if you know the answer then share the answer of any question.
We have a section related to Magento 1 and Magento 2 regarding questions. So you have to ask question related to specific section.
You can check section related to Magento 1 name as,
CORE TECHNOLOGY - MAGENTO 1.X
You can check section related to Magento 2 name as,
CORE TECHNOLOGY - MAGENTO 2
You can also find related information on StackExchange and you can start diving into thehttp://devdocs.magento.com/
You can get idea about already reported/existing issue from Github:https://github.com/magento/magento2/issues
If you're new to our forums, welcome! Take a look around, introduce yourself, check out our guidelines, and be sure to reach out to me or any of our awesome moderators if you have any questions.
You can ask also question to Magento Community Manager @sherrie if you have still issue.
Thanks.
If Issue Solved, Click Kudos/Accept As solutions.