In order to contact your friends in WhatsApp, you can either use the private chat or the public one (chatting in groups). Click on the option shown in the screenshot below in the homepage of WhatsApp so that you can view the list of your friends.
Then you can choose any friend to start a private chat with.
Now you have entered the private chat section.
For starting a public chat, you need to make groups first. In order to do that, choose the WhatsApp menu in the homepage, and then select the specified option “New Group” shown in the screenshot below.
Choose a name for the group and after clicking continue, choose the specified option shown in the next screenshot.
Now you can add or remove any of your WhatsApp friends to join your chat group by clicking or unclicking the checkmark shown beside their names and photos. By clicking “create” you will be ready to start your group chat.
You can have separate chat groups for your family members, friends, and coworkers to make it easier to keep contact with the people you know in the virtual world. Have fun!