There are several synonyms for the phrase "getting into the act" which means to become involved in something or take part in an activity. One such synonym is "joining in", which suggests that the person is becoming a part of a group or an ongoing event. Another synonym is "participating", indicating that the person is actively taking part in a particular activity or event. "Engaging", "involving oneself", "partaking" and "sharing in" are also synonyms for "getting into the act". These phrases all emphasize the idea of actively involving oneself in a situation or activity, rather than just being a passive observer.