Here's a marked-up screenshot for ease of reference:
To customize it, you would go to "Configuration" -> "Order / Invoice Settings" and scroll to the section marked "Bill of Lading Settings". Then you can enter your content into 3 fields.
Then, once you have these sections filled out to your liking, you can download BOLs in two ways:
1 - In bulk from the orders page by checking your selected orders, clicking on "Actions", then selecting "Collate as Bills of Lading". You'll be presented with bills of lading for all of the orders you selected.
2 - On an individual order page, click on "Actions" in the top-right and select "Download Bill of Lading".