You won’t see your static pages change to how that home page would look.
You would need to edit those pages instead.
Does your host offer a staging site option ?
As this would allow you to create a staging copy of your website, where you can import a site from our library, make the changes that will be required without affecting your live site.
Then when you’re happy the host can push the stating site to the live site.
Is there some instructions how deactive published site and choose new one. I dont understand exactly how to do it. At the beginning i made all steps as this video – https://docs.generatepress.com/article/installing-generatepress/
But now I would like to change new site for my premium account. What steps should I do inside wordpress. Maybe you have manuals? I have made backup for my live site.
Have you made changes to your current site after importing the site template?
If not, go to the site library and choose the new template, it will detect your current template and ask if you’d like to get it removed, choose yes, then you can start the new template importing process.
If yes, I would recommend starting the process on a staging site and making necessary changes after the importing, then push the site live.