It will only duplicate if you made the same transactions and imported it twice—once from the desktop data and again from the bank feed in the online platform, Lila. All questions will be answered promptly below.
When you connect your bank account to QuickBooks Online, the system typically imports transactions from the last 90 days by default. QBO doesn't have an option to specify a start date for the initial bank feed download. It depends on what your bank allows.
You can explore this article: Move your QuickBooks Desktop file to QuickBooks Online. For more details about the process of migrating data in QBO.
For future reference on how to manage your transactions in QuickBooks, you can visit these articles:
Feel free to tag me in the comments below if you have any other questions about managing your transactions or migrating your data in QuickBooks. I will respond as quickly as I can.
