Complex sentence: Part one contains the diary entries of the boy in chronological order, as if reading from his diary, which begin on January 1,1885 to emulate his best friend who was to begin keeping a diary in the new year.
Split into simpler sentences: Part one contains the diary entries of the boy in chronological order, as if reading from his diary. The young boy began his daily entries on January 1,1885 to emulate his best friend who was to begin keeping a diary in the new year.