Enemy AI using pathfinding to avoid obstacles

Hello, I am trying to make a TowerDefense game and I want my enemies to avoid the obstacles in front of them and to search for the path to reach their Endpoint. The player will be able to block their way and they need to search for another path. How am I able to make this kind of movement and pathfinding? Can you guys give me some hints? Ive been trying to follow a few tutorials about A* algorith but I am not able to implement the automatically movement on my enemies. Thank you in advance!