Hi Ann,
When you log in to your account online (desktop, laptop) there should be a notification that you can find by clicking on the messages button after logging in. On the phone app, it shows up on the main page where your future reservations show up, right underneath them acutally. If these measures dont pan out, wait a few days and check your email. If that doesnt work, wait a few more days to see if the other party reviews you, which will prompt an email for you to review them back, then if all else fails, or you're bored now and want to call airbnb they'll help you out.
Colin