Complex sentence: The next morning at breakfast Q and Shelby mix up there phones, Q had watched some more of Candace's video and with this new found knowledge Shelby attempts to use this to her advantage to get back with Murch.
Split into simpler sentences: The next morning at breakfast Q and Shelby mix up their phones. Because Q had watched some of Candace's video, Shelby becomes aware of the video and attempts to use this to her advantage to get back with Murch.