What type of lawyer do I need when dealing with mold in an apartment and trying to move out of my lease

The presence of mold, depending on the type, amount, location, etc., may render the apartment uninhabitable. It also will depend on if you created the mold.  You can send a letter (certified mail, return receipt requested) to the landlord advising them of the presence of the mold and give them a time period to remove it and if they do not remove it, then you are going to move out. If they do not remove it, then move out sending the landlord a letter explaining why. You can read about landlord and tenant law in Tennessee through Google.