Like other hobbies in The Sims FreePlay, you must perform specific tasks to receive rewards that complete the Class Clown Hobby collection. There are a total of 12 rewards that are used to complete the hobby. As you’ll see in the tutorial video below, completing a row in the hobby will unlock various rooms in Downtown High. Completing all of the rows will unlock all of the rooms.
The Class Clown Hobby does have a 7 Day Time Limit. Although you have unlimited time to complete this hobby to unlock the rooms in the high school, completing it fully within the time limit will unlock special school-themed attire, like cheerleading outfits with their own unique actions that show off extra school spirit. The end of the video below provides a glimpse at the special outfits and actions.