The lights dim for a second when the fridge kicks on. Is this a problem to worry about or something simple like maybe a breaker going bad.

Neither a problem or anything to worry about. The cpmressor pulls quite a bit of power when it first kicks in and that extra draw can slighlt dim a light for a moment.Are the light and the frig on the same circuit?

Depends a lot on how the wiring was run. If the refrigerator is on the same light circuit, you could expect a momentary voltage stop when the refrigerator kicks on. We don't know your particular circumstance so it is hard to tell you what's happening. How many Amps is main panel rating? Is refrigerator on a separate breaker?

As others have said, I wouldn't worry about it unless you're getting a significant dip in the lights.
Do you happen to know if the fridge has its own circuit?