If you want to import your products and services, you can use the import feature in QuickBooks Online, aldahabiya-kw.
You'll have to make sure to avoid special characters and please know that there's a limit of the import to only 100 characters.
Furthermore, you can follow these steps to import your products and services. If you need help formatting your list, select Download a sample file.
If you want to close your books after the import to prevent any changes, here's an article that you can visit: Close Your Books In QuickBooks Online.
Keep me posted if there are questions about the import processes. I'll always be here to help you if you need further assistance.