Hi @Erin45,
They don't pay a depost to you. Airbnb holds the booking funds and releases it to you via your chosen payout method about 24 hours after the Guest arrives. If that's over the weekend (or similar) then naturally it can take a little longer.
The booking period is automatically blocked out on your calendar on a Reservation is confirmed. You can find the Calendar under the 'Host' menu --> 'Manage Listings' --> 'Calendar & More'.
I'd suggest accessing Airbnb via a web browser rather than the smartphone App and getting comfortable with all the variables. Also dive into the Help Centre and learn all the various aspects of Airbnb.
Cheers,
Paul