To create a group chat, open WhatsApp and go to the 'Chats' tab. Tap on 'New Chat,' then select 'New Group.' Choose the contacts you want to add, then tap 'Next' and provide a group name before creating the group.

To send a voice message, open a chat and tap and hold the microphone icon located in the message input area. Speak your message while holding the icon, then release it to send the recording.

To make a video call, open the chat of the person you want to call. Tap the video camera icon in the upper right corner. The call will start, and the other person can answer to connect.

To change your profile picture, go to 'Settings,' tap on your name or profile picture, then tap on the current picture. You can choose to take a new photo or select one from your gallery.

To back up your chat history, go to 'Settings,' then 'Chats.' Tap on 'Chat backup' and select 'Back Up' to save your chats to Google Drive or iCloud. Set backup frequency if desired. Steps include: 1. Open WhatsApp and go to 'Settings.' 2. Tap 'Chats.' 3. Select 'Chat backup.' 4. Tap 'Back Up' to begin the backup process.