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If you have same pages with same content then you can make one page as your main page and set it as canonical page then it will serve as your main page and then there will be no issue. I have also blog website and I face same issue, I applied that and error was solved.
You can create subdomain as well, that will be also fine. But if you want to move or migration then simply use the migration plugin and it will be simple and hassle free work.