Here is the full list of all 38 Freeman: Guerrilla Warfare achievements.
Land 100 headshots
Kill 100 enemies with grenades
Win 10 battles by yourself
Kill 100 enemies in total
Reach 50 Reputation
Fully upgrade your Stealing skill
Fully upgrade your Agility skill
Fully upgrade your Medicine skill
Fully upgrade your Intelligence skill
Reach Level 30
Reach Level 10
Reach Level 5
Possess 5,000,000 Zolties
Possess 100,000 Zolties
Possess 1,000,000 Zolties
Kill 1000 enemies in total
Land 1000 headshots
Kill 100 enemies with pistol
Kill 100 enemies with submachine gun
Kill 100 enemies with shotgun
Die 50 times
Win 50 battles
Lose 50 battles
Fail at stealing 50 times
Steal 50 times
Plunder 50 times
Recruit all available companions
Throw 200 grenades
Defend your city 5 times
Forge 3 alliances with other nations
Forge 5 alliances with other nations
Construct 50 buildings
Accept volunteer troops 5 times
Have -200 Reputation
Have -100 Reputation
Have -30 Reputation
Reach 300 Reputation
Reach 500 Reputation