You will automatically be signed in to your App after you sign in the first time, but if you want to change the password, simply open the App, open the gear icon in the top right, click “Account” and “Sign out”. Then you can select “Sign in” to the App by entering your email into the username field and selecting the "Forgot your password?" link and following the on-screen instructions.
What if I forget my WiFi Your Way Work App password or I need to change it?