Well......that depends. Getting a manager is not a silver bullet for your career. The old adage is "there has to be something to manage". It's a real catch 22 - it's easy to feel that "I need a job to get a manager, and I need a manager to get a job". In many cases, this isn't true. If you find that a manager is anxious to sign you, and you really don't have any credits yet, put on the brakes - and do some home work. The internet and social media has made these things easy to check. Look at the roster of the person who wants to sign you - where are the singers' credits on the roster. If they are predominantly in pay to sing programs. or companies that you've never heard of, etc., it should be a warning sign. Ask colleagues directly or check the many social media sites about the manager in question. I won't weigh in on this right now, but you will also need to address the issue of retainers.
But to stay more to the side of this that I deal with....We always hold spots open in our auditions for unmanaged singers, and in reality, you have a better shot at getting an audition with me (and I know with some other companies as well) as an unmanaged singer, than you do if you are submitted by an unknown agency that we don't generally deal with. If you have just completed an artist diploma or a young artist program, don't be afraid to use the contacts you have developed to obtain an audition. If any number of my colleagues call and say "you really need to hear this singer", I will. And I will do the same for young singers as well. Don't be afraid to ask for those kind of recommendations. You stand a much better chance of getting an audition that way, than you do if you simply send your materials in blind, or if you sign with an agent, who may in fact, put you even further back in the pack.