How to hide or customize this information?

We definitely do not recommend hiding this, otherwise the user will not know the status of his order and what he purchased. From the screenshot it is clear that the order did not go through hence the course can not be started as order needs to manually approved by the order. For auto approval check woocommerce settings. There is no provision as of now to customise this. It would be great if you can specifically tell us what you need customise and then we can help you out.