Best place to save and secure a freebie download pdf

Where is the best place to save a freebie download pdf and how do you secure it so other files cannot be accessed?

My answer may sound too cliche but you could store your file in a separate folder in Google drive and rest of the files in other separate folders in Google drive itself.
Then you can share the link to download the necessary file to all your subscribees’.
This method is secure enough.

Thank you!
I appreciate the info!