We have an article on ways to do this here.
We have an article on how to do this here.
The Audience Insights tool can be a great resource to analyze different potential audience groups in more detail. Facebook has general information on this tool here.
Facebook has general information on location targeting here. We have a detailed guide to location targeting here.
Lookalike audiences update automatically every 3 to 7 days, as long as you’re still actively targeting ads to the audience.