That's a huge introduction. Are you sure it's not the whole essay that has to be between 1500 - 2000 words?
Anyways, I found a good link about tips to write Autobiography Introductions for you to check out.
WOW THAT'S A HUGE INTRO! Definitely check that out...
Perhaps you could start with a bit of an anecdote or story? I have done a biography (not an autobiography though) earlier this year using that technique. We had a much smaller word limit so it's not as long but here is my intro just to give you an idea of how you could start it:
It’s a sticky summers day in 1979 and Pansy Barnett wipes away a lather of sweat on her forehead as she and her six children stack the shelves in the small stuffy store. Pansy’s husband, Thomas, smiles as a well known customer walks into his humble delicatessen. The customer buys a loaf of bread, which Thomas knows is all he can afford. As the man turns away to tend to his little girl, Thomas slips a carton of milk and a chocolate bar for the child into the paper bag. Thomas couldn’t really afford to give away his livelihood, but his heart was much too large to ever be that of a rich man’s. He had morals, and was far too proud to turn away from them. He was a decent and generous man who valued honesty and respect. He worked hard for his living, an average Aussie battler, who deserved every scrap of food he put on the table. The Anglo-Indian family migrated to Australia in 1969 thus making tolerance, equality, and everybody’s right to a “fair go” among many important principles in Thomas’s life.
Cecilia Donovan, Thomas’ youngest daughter, recalls her childhood and the influence her father had on her life. “He instilled his own code of ethics and ideologies for a fair and just world, in which everybody is respected and tolerated and differences are valued and appreciated, into all of his children, including myself,” Cecilia says. “Without my dad, I would be a very different person. The shop went bankrupt in 1982, but I learnt that kindness and compassion will make a much happier person, than greed and selfishness.”
That was my question- maybe the assignment sheet is misread or mistyped?