Can you get free legal advice for divorce?
Possibly. The best thing to do is to contact the local bar association (just Google the name of the County or Biggest city near you, for instance around here I would Google "Birmingham Bar Association" and go from there.)
From there, call them and ask if they have a pro bono program, or if there are any other pro bono programs in your area.
But definitely, don't let the fact that legal representation can cost money prevent you from looking for an attorney. Family law attorneys will work with you on fees if they can, and will refer you to another attorney if they can't.