making the login pop up to show on nav link click.

I would like to create nav items for guests to see what is on the site, but when they click on it, the join/login form pops up like if I click the join button.

Is this an install without any changes to it?  If so, then this needs to be reported as a bug unless it is something you have done.  Adding a navigation link should not cause the join form to pop up.

 I believe he was trying to say  this:

would like to create nav items for guests to see what is on the site, and when they click on it, the join/login form pops up as if I click the join button.

Ok here it is:

I would like to create nav items for guests to see what is on the site without them having permissions to view the content, so when they click on the nav item, the join/login form would pop up as if they were clicking the join button. I think this will encourage them to join. I like the join/login popup.

Wow, what a difference in context between two simple connecting words.