It's a love story between a boy and a girl living in Indiana who met at a cancer patients group living in Indiana.

There are many words and expressions I don’t know, so at first each time I encountered them I looked them up in the dictionary, ¶
but I gradually I ignoredstopped looking them up and continued reading.

So I'm not sure if I could understanood the story completely.

AndI also felt the same when her boy friend died, and the book author came all the way to Indianapolis for the funeral.

Book Review 《THE FAULT IN OUR STARS》by John GreenOPTION A: A Review John Green's 2012 "THE FAULT IN OUR STARS" ¶
OPTION B: Some Impressions of John Green's "The Fault in Our Stars" (2012)

PUNCTUATION POINT: Double-carat characters 《》are not so commonly used in English, but they do exist in some styles. (Cf. https://www.scribbr.com/citing-sources/cite-a-book/ )

私の好み：I finished reading theJohn Green's sixth book and best-selling book yesterday.

It's a love story between a boy and a girl who met at a cancer patient's group living in Indiana.

SoAs a result, I'm not sure if I could understanood the story completely.

And also when her boy friend died, the book author came all the way to Indianapolis for the funeral.

Book Review 《THE FAULT IN OUR STARS》of "The Fault in Our Stars" by John Green

It's a love story betweenabout a boy and a girl who met at a cancer patients group livingsupport group in Indiana.

There awere many words and expressions I don’idn't know, so atwhen I first each time I encountered them, I looked them up in the dictionary, ¶
but gradually I started to ignored them and continued reading.

Since you're writing about the past, it needs to be changed to "there were" and "didn't know."

So I'm not sure if I could understanood the story completely.

"Understood" has to be used because you're writing about the past.

And also when her boy friend died, the book's author came all the way to Indianapolis for the funeral.

It's a love story between a boy and a girl who met at a cancer patients group livingsupport group in Indiana.

There awere many words and expressions that I doidn’t know, so at first each time I encountered them, I looked them up in the dictionary each time I encountered them, ¶
but gradually I started to ignored them and continued reading.

So I'm not sure if I could understanood the story completely.

And also when her boy friend died, the book author came all the way to Indianapolis for the funeral.

It's a love story between a boy and a girl who met at a cancer patients group living in Indiana.

"cancer patients group living in Indiana." sounds like the group is living in Indiana

There are many words and expressions I don’t know, so a. At first each time I encountered them, I looked themeach one up in the dictionary, ¶
but gradually I ignored them and continued reading.

"so" indicates a cause-affect relationship

And also when her boy friend died, the book author came all the way to Indianapolis for the funeral.

Book Review 《THE FAULT IN OUR STARS》of "The Fault in Our Stars" by John Green

It's a love story between a teenage boy and a girl who met at a cancer patients group living in Indiana.

There awere many words and expressions I don’idn't know, so atwhen I first each time I encountered them, I looked them up in the dictionary, ¶
but grad. Eventually, I started ignoreding them and continued reading.

So I'm not sure if I couldfully understanood the story completely.

I didn't get bored while reading, but I felt it was a bit contrived when the girl wanted to know the ending of the book she read ¶
was reading and went to visit the author in Amsterdam.

And also when her boy friend died, the book's author came all the way to Indianapolis for the funeral.

It's a love story between a boy and a girl who met at a cancer patients group, both living in Indiana.

There are many words and expressions I don’t know, so at first, each time I encountered them I looked them up in the dictionary, ¶
but gradually.¶
Gradually, however, I ignored them and continued reading.

I didn't get bored while reading, but I felt ithe plot was a bit contrivforced when the girl wanted to know the ending of the book she read ¶
and went to visit the author in Amsterdam.

そうですか？なんて発想だなー

And alsoOr when her boy friend died, the bookat same author came all the way to Indianapolis for the funeral.

キモい！知り合いだけじゃない？

Book Review 《THE FAULT IN OUR STARS》of "The Fault in Our Stars" by John Green

It's a love story betweenabout a boy and a girl who met atin a cancer patients group livingsupport group in Indiana.

Rephrased it to be a bit clearer.

There are many words and expressions I don’'t know, so at first each time I encountered them. Initially, I looked them up in the dictionary every time I encountered them, ¶
but gradually, I started ignoreding them and continuedjust kept reading.

Starting a new sentence keeps it from running on too much.

I didn't get bored while reading, but I felt it was a bit contrived when the girl wanted to know the ending of the book she read ¶
and went to visit the author in Amsterdam.

I don't think "contrived" is the right word here. What were you feeling? Did you think the girl was being a bit excessive in her efforts to meet the author? I think "overdone" or "forced" might be a better word in that case.

And also when her boy friend died, the book author came all the way to Indianapolis for the funeral.

BookA Review 《of the book "THE FAULT IN OUR STARS》" by John Green

It's a love story between a boy and a girl who met at a cancer patients group living support group in Indiana.

SoTherefore, I'm not sure if I could understanood the story completely.

I didn't get bored while reading, but I felt it was a bit contrived when the girl wanted to know the ending of the book she read ¶
and went to visit theits author in Amsterdam.

I'm not sure "contrived" is the word you want. I have corrected as best as I can.

And also when her boy friend died, the book's author came all the way to Indianapolis for the funeral.

It's a love story between a boy and a girl living in Indiana who met at a cancer patients group living in Indiana.

The order I've used is easier to read, but if you want to keep something close to the original order, you can replace "living in Indiana" with "in Indiana", but then this would instead modify "cancer patient group".

And alsoSame with the part when her boy friend died, how the book author came all the way to Indianapolis for the funeral.

Note that this is not a complete sentence, but it's acceptable outside of formal writing.