Thank you for your reply.
I’ll clarify what I’m doing.
I’m changing my blog completly (new domain, new serwer, new theme, new pages etc) but I want to keep the old content (grouped under one category).
I have already created new blog (new domain, new pages etc.) and copied the old ones content and database. It is basically ready to lunch but I want to redirect the traffic from the old URLs to new ones.
For example:
https://www.olddomain.com/index.php/09/01/2016/Post-about-cake
to
https://www.NewAwesomeDomain.com/Post-about-cake
…and 1999 posts more ??