This answer shows how to require a user to make a copy of the Google Doc you share with them so they can't edit the original.
For these instructions, please have a Google Doc ready for sharing.
You can invite people now or later.
Change Who Has Access
At the top of the Who has access list, click Change
At the very end of the URL you just copied and pasted, find edit?usp=sharing and replace it with copy. When people copy the new link, they should see the following picture.
Users will select to Make a copy before viewing the document.