Finding bachelors isn't very hard at the very beginning since every sims that isn't married is not attached.
In my experience most singles are the service sims i.e. maids, firefighters, repairmen etc.
But at the beginning these people are also individuals that are single at the start. Morgan Flynn, Trevor Burton, Cevin Faron and a couple of others that I forget the names of. the thing is they are there you just need to look at places that have lots of people coming and going.
Like the Gym, the Theater or even the Library.