It's good to see you here, ilancealota.
The transactions you enter in the sample company or the QBO Test drive will be deleted when you log out or close the page. This is just for training purposes so you'll be familiar with how QuickBooks Online works and its features.
You'll need to record all your transactions into your real account so they'll be saved. Click this link so you'll be routed to the login page.
Also, you can always visit our QuickBooks Help page if you need articles and references for managing your business.
Please post again if you need anything else. Wishing you all the best!