How to make blog for more persons with own pages?

You have posted the solution ??
It is clear from the URIs you posted that every author is a “category”.
Create a category for every user and you are done.

But when I creat another category, link is for example “https://www.rogner.cz/?cat=2”

But I need “https://www.rogner.cz/category/roman”

You need to set up your permalinks.

Also, check for the different multiple blog plugins which may help.