How do I move data from a trial account to an already purchased account in quickbooks online?

You'll need to move the data manually, Leonard.

While there isn't a direct way to merge the trial and fully paid account, you can instead export the data from the trial account and import it into the paid account.
 

Here's how:
 

1. Log in to the trial account.
2. Go to the Gear icon and choose Export data.  
   
3. Select the necessary data you want to export and click Export to Excel.
4. Once done, log in to the paid QuickBooks Online (QBO) account.
5. Navigate to the Gear icon and select Import data.
   
6. Choose the type of data you want to import and hit Import.
7. Follow the onscreen prompts. 
8. Review and confirm the mapping of fields to ensure the information transfers correctly.
    

I've also added this article to learn about some frequently asked questions about importing data: Common questions about importing data to QuickBooks Online.
 

I'll still be here if you have further questions about moving your data.