Hi accessrose, a short and simple CSS rule like this should do the trick:
#tribe-events-pg-template { background: white }
If your theme has somewhere that you can add custom CSS you might be able to quite easily add this there, or you could just add it to the bottom of your theme’s own stylesheet. Otherwise you’d have to either use Andy’s plugin (as referred to by Rob) or else read through the Themer’s Guide and learn about creating a tribe-events.css stylesheet:
https://theeventscalendar.com/support/documentation/events-calendar-themers-guide/
If there is anything specific in there you don’t understand then definitely let us know and if we can prod you in the right direction we will 🙂
Hope that helps!