Hi Jim and welcome to the forums!
The featured venue shortcode requires you to specify the venue you want to display. So, for example, if you have a venue called Starbucks, you can add the venue slug to the shortcode like this:
[tribe_featured_venue slug="starbucks"]
Then, to limit the number of events to three, you can add that to the shortcode as well:
[tribe_featured_venue slug="starbucks" limit="3"]
You can find full details about all of the shortcode’s available options in this post.
Does this help answer your question? Please let me know. 🙂
Cheers!
Geoff