@Doreen75 You need to go to the Airbnb site and read everything in the Help pages for hosts. All the basics are explained there and it works much better to read through everything before putting your listing up. There is much more that you will need to know about.
When a guest books, they are charged by Airbnb. When the payment is collected, you should see "reservation confirmed" on the booking. Airbnb will hold the money until 24 hours after a guest checks in. Then it can take a few more dyas to appear in your bank account, Paypal or whatever payout preference you have chosen I assume you have filled out this info in your profile?). New hosts have to wait up to 30 days for payment for the first reservation, after that, they should come 24 hours after check-in.