I need to add 'track your order' tab in home page that will be visible to all but only logged in customer can use to track orders?
By default in Magento transnational notifications can be sent to the customer by selecting an option while performing actions on the order.
For Example :
Step 1: Your receive Order
The default status will be in pending
Step 2: When you Generate invoice or Shipment you have an option to notify customer if you select that option.
A notification email will be sent to the customer with the respective order update.
Step 3: If both invoice and shipment are generated the status will be updated as complete.
A notification will be sent to the customer as the order has been completed.
Apart from email notifications the customer can login to your store and check the order status