Open WhatsApp. It's the green app with a white phone icon on it. If you haven't yet set up WhatsApp, do so before continuing.
Tap the Chats tab. This option is in the top-left corner of the screen. You'll see a list of your existing chat conversations appear.
If WhatsApp opens to a conversation, first tap the "Back" button in the top-left corner of the screen.
Tap a conversation. Doing so will open the conversation with the corresponding contact.
You can also tap the green "New Message" icon in the bottom-right corner of the "Chats" page and then select a contact to create a new message.
