Texte Anglais TS

Bonjour, je suis en terminale S et je voudrais m'entrainer pour le bac d'anglais à l'aide d'un texte qui se trouve sur mon manuel scolaire (ci-dessous), bien que je comprenne quelques points, j'ai vraiment du mal à comprendre l'histoire et donc a répondre aux questions. Pourriez vous me mettre sur la voie s'il vous plait ? merci d'avance :)

Trick or treat ?

Mrs Dunbar is writing an "annual holiday newsletter" to let her family and
friends know about what happened during the year.
To those of you who live in a cave and haven't heard the news, allow us
to introduce Khe Sahn Dunbar who, at the age of twenty-two, happens
to be the newest member of our family.
Surprised?
JOIN THE CLUB!!!!!!!
It appears that Clifford, husband of yours truly and father to our three
natural children, accidentally planted the seeds for Khe Sahn twenty-two
years ago during his stint1 in ... where else?
VIETNAM!!!!
This was, of course, years before Clifford and I were married. [...]
Clifford Dunbar, twenty-two years ago, a young man in a war-torn country,
made a mistake. A terrible, heinous mistake. A stupid, thoughtless,
permanent mistake with dreadful, haunting consequences. [...]
When his tour of duty ended Clifford returned home, where, after
making the second biggest mistake of his life (I am referring to his brief
eight-month "marriage" to Doll Babcock), he and I were reunited. We
lived, you might remember, in that tiny apartment over on Halsey Street.
Clifford had just begun his satisfying career at Sampson Interlock and
I was working part-time, accounting for Hershel Beck when ... along
came the children!!!!!! We struggled and saved and eventually (finally!!)
bought our house on Tiffany Circle, number 714, where the Dunbar clan
remains nested to this very day!!!!
It was here, 714 Tiffany Circle, where I first encountered Khe Sahn, who
arrived at our door on (as fate2 would have it) Halloween!!!
I recall mistaking her for a Trick-or-Treater! She wore, I remember,
a skirt the size of a beer cozy3, a short, furry jacket, and, on her face,
enough rouge, eye shadow, and lipstick to paint our entire house, inside
and out. She's a very small person and I mistook her for a child. A child
masquerading as a prostitute. I handed her a fistful of chocolate nougats,
hoping that, like the other children, she would quickly move on to the
next house.
But Khe Sahn was no Trick-or-Treater.
I started to close the door but was interrupted by her interpreter, a very
feminine-looking man carrying an attaché case. [...] Khe Sahn responded
to the interpreter, her voice as high-pitched4 and relentless as a car alarm.
The two of them stood on my doorstep, screeching away in Vietnamese
while I stood by, frightened and confused.
I am still, to this day, frightened and confused. Very much so. Out of
nowhere this young woman has entered our lives with the force and
mystery of the Swine Flu5 and there appears to be nothing we can do
about it. Out of nowhere this land mine knocks upon our door and we
are expected to recognize her as our child!!!!????????
David Sedaris, Holidays on Ice, 1997.

D'après ce que j'ai compris, Mrs.Dunbar raconte ce qu'il s'est passé le soir de Halloween concernant une certaine Khe Sahn qui ferait maintenant parti de leur famille depuis qu'elle a sonné a leur porte ce soir là. Je sais aussi que cette fille a 22ans, mais je pense vraiment pas que je sois sur la bonne route :/ Merci de m'aider.