Website has endless loading with nothing actually rendering

Pages have an endless loading spinning circle. Page loads sometimes if I refresh but most of the time doesn’t. Same issue in different browsers.

WPMU DEV support said it was an issue with the theme:

“On further inspection, I found multiple JavaScript errors on the frontend from the console mainly suggesting that jQuery is not loaded. This could be the theme’s issue. Theme could have dequeued jQuery. So we suggest asking the theme author regarding the issue.”

Not sure what to do from here. Any ideas?