Open the Notifications panel and tap New voicemail.
OR
Tap the Voicemail icon on the Home screen.
OR
From the Home screen, tap the Phone Key in the Quick Keys bar, then tap the Voicemail Key . Typically, your carrier’s voicemail system guides you through the process of listening to and managing your voicemail. The first time you call your voicemail, it also guides you through the process of recording greetings, setting a password, etc.