Novice for changing font and positioning

Hi, I’d like to be able to modify the font size and possible the formatting (bold/italic etc) for the events. I’m not sure how to do this, I’ve read up, and I hear lots about about setting up css pages, of which I have no clue to, is there a code I can simply copy and paste in to my theme’s ‘Custom CSS Box’?

Also for some reason the text is slightly indented by a few. Thanks!

https://www.ads-software.com/plugins/event-list/