Well, it's hard to say. It could be that 'a guy like you' is a reference to a certain type of character often found in manga about bums. Or perhaps it's the title of a manga series that involves a guy who's considered a bum. But without more context, it's just speculation.
Yes, 'The Beach Bum' is somewhat based on a true story. It draws inspiration from real - life beach - bum cultures and the laid - back lifestyles often found in coastal areas.