Story related, impossible to miss.
you'll receive some information on how to use commands letting you exit the first bunker, getting the pistol and killing a couple of foes.
out of the bunker just follow the compass to find a village, pick up the ammos and go find binocular up the tower, near there.
After that you'll have to face your first tricky situation: stole a car a run away from a camp. My suggestion is to run directly to the car ignoring the foes, then drive all the way following the compass.
You'll eventually run over some enemies, fine for another achievo, until a beach where you'll face enemies on a car.
Kill them all and take the foes' car then again follow the compass.
Up the hill and down into the water, now you just have to reach the boat and the mission is done... As well the achievement will pop