Recently, The Shanghai's air quality is so bad, L that lots of dust is in the air.

you may also say:

Recently, Shanghai's air quality is so bad. There is lots of dust in the air.

Yesterday afternoon, I attended a meeting and it finished earlier than susexpected.

It was a good time for washing cara car wash,

you may also say:

It was a good time to wash my car
It was a good time for car washing

The sunlight and temperature were so fittedjust right.

or The sunlight and temperature were (just) perfect

note 1) you cannot say "The sunlight and temperature were right." though
note 2) Usually when describing sunlight, you may want to use "the level of sunlight" or "the amount of sunlight". So it would then become "The amount of sunlight and the temperature were just right."

Thaen I used a bucket of water and spent a half ofan hour to clean my car by myself.

It was no any fare andfree and I get to exercise my body.

Recently, The Shanghai's air quality iwas so bad, L there was lots of dust in the air.

"The" does not need to be present here, and does not sound natural. Shanghai, like most other proper nouns, does not need the article in a use-case like this.

So, my car is very dirty, too.

"So" needs a comma after it, as well as "too". Whenever "too" is used at the end of a sentence in English, we write ", too".

It was a good time for washing my car,.

The sentence needs an article ("washing a* car"), or an adjective ("washing one* car", or a possessive adjective ("washing my* car")

The sunlight and temperature were so fitteding.

"Fitting" works here, but is not common to say where I live. We might say something like, "The sunlight and temperature were just right." Perhaps, we might say, "The sun and temperature were just right."

Thanen, I used a bucket of water and spent a half of hour to cleaning my car by myself.

It is very easy to accidentally use "than" instead of "then". We English speakers do it all the time :). Than is used just for comparison. For example: The orange cat is bigger THAN the grey cat. OR The younger guitarist has less skill THAN the older one.

It was not any fareir, and it really exercise d my body.

I'm not sure of the meaning in this sentence, but I tried to make a suggested change according to what I guessed you were trying to say. I believed you were saying that it was not fair (that you were doing this by yourself), and that you exhausted yourself with exercise.

Recently, The Shanghai's air quality is so bad, Lots of dust in the air.

Yesterday afternoon, I attended a meeting and it finished earlier than susexpected.

It was a good time for washing a car (or: cars),

The sunlight and temperature were so fittedperfect (or, closer to your sentence but sounding less natural: so suitable).

"Fitted" is only used for physical objects; generally for tight-fitting clothes, I think.

Thaen I used a bucket of water and spent a half of hour to cleaning my car by myself.

It was no any fare and exercise body.

I don't understand this part, especially "no any fare"