Welcome to the Community, @Jean22.

If you just opened your QuickBooks Online (QBO) account, you can remove all the information added to start over. This process will delete all the data in the company file. Here’s how to do it:

1. Log in to your QBO account. 
2. Change the URL to include /purgecompany. From https://qbo.intuit.com/app/homepage to https://qbo.intuit.com/app/purgecompany. 
3. The next screen will provide a summary of the items to delete.
4. Type YES to delete the data, then select OK.

For thorough instructions, check this article: Delete your data and start over in QuickBooks Online. Also, see this common questions about importing data to QuickBooks Online article for more information.

I'm always here if you need further help with your company file. Have a wonderful day!