SALEM — Two years ago, Andrew Turner had no specific plans to become an entrepreneur. He liked his job in business development at Aerial Spectrum in Burlington and figured he would be there a while.

But the entrepreneurial fire kindled quickly when Turner, 31, was laid off in June 2011, and he decided to create his own job. Now, as a Billerica agent for car buyers, he is among the region’s expanding ranks of young adults who have left the 9-to-5 commuter life and embraced the adventure of running their own companies.