You cannot get a blue tick in WhatsApp for your own account
WhatsApp blue ticks are read receipts shown when the recipient reads your message
To see blue ticks, the other person must have read receipts enabled
If the other person disables read receipts, blue ticks will not appear
In group chats, blue ticks appear when all participants have read the message
You can enable your own read receipts in WhatsApp settings if you want others to see when you read their messages
Open WhatsApp
Go to Settings
Tap Privacy
Turn on Read Receipts