If you need to obtain a buyer name and email in exchange for the free sample and need to issue downloads using our unique and expirable links, you can just set a product's price to 0.00 when you follow our standard Add Product procedure:
Buyers who Add to Cart the free product (and no other regular-price product) will be offered a Free Checkout option in their cart, which will take them to enter their name and email address before being given their download link (company and phone are optional, but you can make Phone required in Seller Admin > Payment Preferences). Our system can process up to 100 such Free Checkouts for you per day.
If you just want to give away free samples without asking any info in return, you can just upload the file to your Web site and make a regular HTML link to that file, just like you'd make a link to another page. You could even have an ordinary contact form where the user enters some contact info and then Submits that form to reach a thanks page where a plain HTML link to the free sample file is shown. These approaches would not involve our system at all and would be entirely up to you or your Webmaster.