I am part of an NDA project, and before anyone onboards the project, we need them to read an NDA disclosure and agree to the terms and conditions. Is there a way we can add a page on confluence that allows team members to click a button that confirms they have read the terms and conditions (but not give them access to any other pages on the confluence page), and we can track who has confirmed the T&Cs?
You have to restrict the other page so people can't access them. By restricting, you can decide a group people can see or some people, more info: https://confluence.atlassian.com/doc/page-restrictions-139414.html
Are you saying other confluence, except the one you created where they have to Accept the NDA?
Here is an existing plugin for what you need:
If you want another way but free, you can create a page with the name of the person, restricted to only the person, put at the end of the page, a "Checkbox" with the criteria where people read and understood your policy.
I hope it helped.