A 2G MIG cert is a good starting point, but is not worth a lot by itself.
It's kind of like going to apply for a job in a restaurant as a Chef and saying "All I know how to cook is fries, but I can cook them real good."

The best way to get started depends a lot on where you are located and if you're willing to travel for work.
Some employers hire Welder's Helpers, which is a great way to get paid while learning the business. Other places have in house training programs to help build skill of entry level welders, while some have apprentice programs.
It all depends on what's available in your area.

The biggest hurdles toward getting a good job are not so much skills, but attitude, appearance, references and the ability to pass drug tests and background checks.

Tim