I am working on a document that has a lot of very important disclosures. I
would like the users of this doc to read the disclosure tab before they
proceed to the actual document. I was thinking about creating a pop-up box
that would open when they click on the doc tab (it would say "I've read and
understand the disclosures" or something along those lines). Or maybe a
pop-up box to ask them if they agree and would like to proceed.

Any idea on how to do this?

Thanks!