If you are talking about the monsters in the jungle then get help from your people in the lanes near you early in the game. They can help soak up some damage and deal out some damage and give you the buff XP. After the first 3 levels clearing camps is easy as long as the enemy keeps out.
You can break those turrets only when your minions are pushed up to it or you have a tank on your team soaking the damage as they will always kill you on sight unless there is another target such as minions. Also note that if you attack an enemy champion under the tower the tower will aggro to you and you betta run.