Notification set up is going to be done in your profile. You can get to your profile at the top right hand side of the main menu bar.
1. Open up your profile and select Edit
2. Under the Settings section of your profile, you will find the various types of notifications that you can receive. You can opt to accept system, email, and/or text notifications. Important: the mobile number entered in your profile is going to be the number the text notifications go to.