The fallacy that is being committed in "Either you go to college or you will be a bum." is the false dilemma.
A false dilemma fallacy refers to the fallacy that gives choice between two mutually exclusive options. It is also called the either/or fallacy
A False dilemma is an informal fallacy where a faulty argument is used to convince an audience to agree to a particular point. Since the statement is "Either you go to college or you will be a bum.", it's a false dilemma fallacy.