The phrase "started something" can have a variety of synonyms depending on the context. To initiate an action or event, one could use terms such as "commenced," "launched," "initiated," or "inaugurated." For more informal situations, one may opt for phrases like "kicked off," "got things rolling," or "set the ball in motion." "Embarked on" is another synonym that can indicate the beginning of a journey or project. Additionally, "triggered," "prompted," or "instigated" can convey a sense of starting something by inspiring or motivating others. Whatever the case, there are many synonyms available to express the act of beginning something new.