I have a contribution page here https://flbc.edu/donate/flbc-donation/, but when I click on confirm it just brings me back to the same initial page. It was working before and I just upgraded to the newest Civi and now it is not working. Any ideas why this might be happening?
When reproducing your experience, I see:
flbc.edu/:1 Uncaught SyntaxError: Unexpected token '<'
It shows it on the initial page load as well as after submitting. And the province selector after selecting a country is also broken, that's probably a symptom of the same problem.
When I look at the html source of your page, I notice that it ends with:
That's bad - you're not getting your closing html or body tags output.
Conclusion: I suspect you might be hitting some kind of server limit (your page has a lot of css/js loaded).
Do look at your server logs, there's probably a hint in there. I don't think it's CiviCRM-specific.