To start out, you must be playing as Michael, as he is the only that can initiate these missions. Access his phone and visit the internet. Enter www.epsilonprogram.com and complete the Identity Evaluation. It doesn’t really matter how you answer because you will get a report that mentions a dented red truck either way.
A “?” will appear on your map at Raton Canyon on a road between Mount Josiah and Cassidy Creek. This is the first mission in the line.