Main takeaways:

Renzo Gracie shows one of the most basic attacks for you to apply from the mount, especially when your opponent closes up, flexing their arms and protecting their neck. It's the americana. Note how Renzo, as he controls his opponent's wrist, puts the weight of his entire body over that wrist, making the arm capture and the submission adjustment that much easier. Pay attention to the type of grip Renzo picks to attack with, making escaping harder.