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If you’re an undergrad that makes things much easier anyway. Join a few clubs related to stuff you’re already interested in, socializing more will build up your confidence then you can decide if you want to start a leftist club. Also, there’s probably several already on your campus, if your undergrad TAs are unionized you can try getting a job as a TA and start attending meetings there. There’s usually communists in most union meetings, even moreso for university student-worker unions.