Hello Mark,
Thanks for going Pro and for reaching out with your styling question!
Although I cannot give you a detailed list of what-who-how you can style all the elements, I can help you get started.
As a first I recommend this article as a base:
https://theeventscalendar.com/knowledgebase/stylesheets-and-page-templates/
If you are thinking about creating your own page templates, then this is your best bet:
https://theeventscalendar.com/knowledgebase/themers-guide/
And this article shows you some basic modifications, but it also gives you some tips how you can do a whole lot more.
https://theeventscalendar.com/knowledgebase/changing-fonts-and-colours/
Let me know if this helps.
Cheers,
Andras