How can I change the URL?

Question

URL Handling

When I created the site about the cnc, I didn’t know anything, and since the domain is in the rf zone, all my URLs are in Russian. But as it turned out later, the search engine does not really like such URLs and I want to remake them so that they are in English. But I'm afraid that there will be duplicate pages and that I will lose links to these pages and they will sink in the search. How can this problem be solved? Or do not touch these pages anymore, but create new ones taking into account the CNC?