How to transfer the entire site from the main domain to the subdomain?

Question

Google

Hello everyone, I am transferring the entire site from the main domain mydomen.com to the subdomain ru.mydomen.com
on the main domain put a 301 redirect to the same page of the subdomain:
mydomen.com/q/1/ => ru.mydomen.com/q/1 / The
question is:
If google visits ru.mydomen.com/q/9999/ without going to mydomen.com/q/9999/. That is, he will not know that the page was transferred, he had already indexed it before (mydomen.com/q/9999/).
Will Google think that the content is copied?
Or will he go to mydomen.com/q/9999/ and get his redirect?
How to transfer all pages to a subdomain?

Answer 1

For Google - https://support.google.com/webmasters/answer/83106...
For Yandex - https://help.yandex.ru/webmaster/yandex-indexing/m...
Thanks evnuh

Answer 2

https://help.yandex.ru/webmaster/yandex-indexing/m...