Login to the backend
To check orders go to woocommerce->orders from left hand side
To change the order status click on particular order and change the status
Check below Screenshot for reference.
To perform different order actions such as send invoice, new order notification click on order action and select particular action and click on update. Note: Only do this if required. By default this will automatically work.
Please check the screenshot below for reference.
To check whether you received payment or not you can go to https://razorpay.com/ and check the status over there.
You can check all the customers go to woocommerce -> customers