Everyone needs regular breaks, like lunchtime, which should be marked as 'unavailable' in your calendar to avoid any bookings during these slots.
Here's a simple way to do it:
Navigate to the 'Availability' tab and choose '+time off' from the top of the screen.
If your lunch break is from 12:00 PM to 1:00 PM daily, for example, set this time and schedule it to repeat every day.
If this break applies to the entire team, select 'any resource'. But, if each team member has different schedules, you'll need to set 'time off' individually. Simply repeat this process for each member.
This will ensure no appointments overlap with your break times.