How does the creature say he learned to live in the world in Frankenstein?

He learns the same way we learn-by
experience. Of course, he is at a disadvantage, having no parent there to
guide him through his trials. But he slowly learns to "distinguish [his]
sensations from each other": recognizing forms, light, sound, etc. He
also learns to use tools, wielding fire to his advantage after burning himself
once.

One
day, when I was oppressed by cold, I found a fire which had been left by some wandering
beggars, and was overcome with delight at the warmth I experienced from it. In my joy I
thrust my hand into the live embers, but quickly drew it out again with a cry of pain.
How strange, I thought, that the same cause should produce such opposite effects! I
examined the materials of the fire, and to my joy found it to be composed of
wood.

Essentially,
he learns scientifically, through observation. These chapters represent a
child taking his/her first steps in the world, slowly discerning each new
sensation.