Hi @teamduce,
Great question. There are actually quite a few ways you could do this depending on the fine detail of what you want to achieve and what sort of methods you feel most comfortable with.
The easiest method might be to use the Default Events Template setting and add an appropriate snippet to the default-template.php template (you can override and customize nearly all of our templates with ease). Alternatively you might use one of our many hooks such as tribe_events_before_html – in general though you will find lots of useful information throughout the following resources:
I hope that helps!