When I got QBO tonight, apparently all of my payroll items didn't migrate. It is asking me to enter it all manually. What happened?

Welcome to the Community, @madalaineh-gmail. I appreciate you for using Quickbooks Online for your business. 

When you start using QuickBooks Online Payroll, you'll need to enter your company wages and taxes for each payday in the current quarter to ensure you're not missing any historical paychecks. 

Here's how:

1. Go to the Payroll menu, then select Employees.
2. Locate the employee's name, and then click Edit employee.
3. Scroll down to Step 8: How much did you pay [employee] this year?
4. Click +Enter [year] prior pay details.
5. Hit Done.

After you enter the pay information, repeat the same steps for your other employees. Here's an article to guide you more in setting up a prior payroll for QuickBooks Online Payroll.

Let me know if you have additional concerns about using QuickBooks for your payroll. I'll be there to help you again.