If you have demo data in your account after setting up a trial, you can quickly remove all the demo data with one click. (Demo data can be quickly identified as all the contacts in the associated leads and bookings have the surname "Brite").
Settings
Go to settings, then >> Data Types, then >> Import.
If you have demo data in your account, you will see the yellow banner below. To remove the demo data, just click on the banner, and the demo data will be removed.