Note: When you use the right thumbstick to highlight enemies, those highlighted yellow are safe to take down whereas enemies highlighted red can be seen by other enemies. Once there, use the bushes and the vegetation walls to quietly take out all the guards patrolling the area. Climb up the wooden wall and proceed to the next area. Take down the person operating the generator and then go to left. Shortly after that, you'll get to the game's first real combat area. Once the cutscene ends, begin running through the cave and breakdown the wall at the end using the pickax.
Move to the right and then rappel down until you trigger a cutscene. When you get to the end of that pathway, Wall Scramble up to the golden-colored ledge. Otherwise, there wouldn't be enough time. Use that to jump onto the first platform and then onto the ladder. Run up to the ledge on the right side instead. In order to get to the ladder that the cutscene shows, don't go back the way you came from.