By default, WhatsApp will automatically set your privacy settings to allow any WhatsApp user to view your last seen, profile photo and status. If you don't share your last seen, you won't be able to see other peoples' last seen. Please note there is no way to hide your online status.
To change these settings, simply go to WhatsApp > Settings > Account > Privacy.
You can set the following options separately for last seen, profile photo and/or status.
Your last seen, profile photo and/or status will be available to all WhatsApp users.
Your last seen, profile photo and/or status will be available to the contacts from your address book only.
Your last seen, profile photo and/or status will not be available to anyone.
To block any contacts that are stored in your phone, tap on Blocked in your privacy settings. For more information on blocking contacts, see this FAQ.
You can turn off the Read Receipts feature such that you will not send Read Receipts for the messages you receive, nor will you see Read Receipts for the messages you send. For more information, see this FAQ.
WhatsApp Support Team