Complex sentence: While adjusting to life with his step-sister Ashley, Toby is unhappy because they don't get along, so Toby convinces J.T. to run against Ashley in the school presidential race.
Split into simpler sentences: While adjusting to life with his step-sister Ashley, Toby is unhappy because they don't like each other. So Toby convinces his friend J.T. to run against Ashley in the school presidential race.