No matter how good you are, when you get to the professional world, you will be competing against thousands of people who are better. So, there is no "good" … there is no "good enough" … there's only the never-ending pursuit of being stronger. Start now.
Agencies are the best starting place for anyone launching a Hollywood career… even if you don't want to be an agent. Many networks, studios, and producers won't even hire assistants who don't already have agency experience.