When you enter the app for the first time, you will find the most recent deals on the home page under Hot Promotions, you can tap on a specific deal or you can select See all to go to the timeline of Promotions.
If you have forgotten your password, on the login page it has a Forgot Password option near the bottom of the screen, follow the directions as it instructs.
Please check again, how did you login the first time. - Using your email - Using your G+ - Using your Facebook You did not have a username or password when you originally logged in, because you might have logged in using different method, which are ...