Knowing English increases your chances of getting a good job in a multinational company within your home country or for finding work abroad. It's also the language of international communication, the media and the internet, so learning English is important for socialising and entertainment as well as work!
The speaker's forehead is described as a wall, which probably means that he has a high forehead and that it is probably a very visible forehead that seems to rise above the rest of the face like an imposing wall would rise above a landscape.
The eyes are described as caves, which means that they were probably dark in color and significantly inset into the head. Having deep eye sockets would give the impression of having eyes at a great distance from the rest of the face due to being in a type of cave.
