One phrasing you can adopt is this.

 Rather than writing  "benefits and denuciations";  you can use this phrase which reads a little more smoothly:

  "benefits and detriments"

Just break down the question.

"Advertising is all around us, it is an unavoidable part of everyone's life." - do you agree or disagree? Why?

"Some people say that advertising is a positive part of our lives" - why do you think they would say that? Do you agree with their opinion?

"while others say it is a negative one." - same question as above.

No-one's here to write your essay for you.  Give a couple of ideas and we can give you some advice. 

Can't stop, I'm "on a roll..."

This is a famous humorous poem by Ogden Nash. Billboards are large outdoor advertising signs. 

"Song of the Open Road"

I think that I shall never see

A billboard lovely as a tree;

Indeed, unless the billboards fall

I'll never see a tree at all.

--Ogden Nash, 1941

Nash's poem complains about billboards. It also pokes fun at a famous serious poem U.S. students used to memorize in school, which began "I think that I shall never see/A poem lovely as a tree." In fact it pokes fun at two poems, the title "Song of the Open Road" being the same as one by Walt Whitman)

A 1965 law put strict limits on advertising on the Interstate highways. The law was passed because of a personal campaign by the "first lady", the wife of the President, "Ladybird" Johnson. There are now wonderful scenic views from the interstate highways.

"I'd like to know what sort of trading isn't a swindle in its way. Everybody who does a large advertised trade is selling something common on the strength of saying it's uncommon. Look at Chickson—they made him a baronet. Look at Lord Radmore, who did it on lying about the alkali in soap! Rippin' ads those were of his too!"
"You don't mean to say you think doing this stuff up in bottles and swearing it's the quintessence of strength and making poor devils buy it at that, is straight?"
"Why not, George? How do we know it mayn't be the quintessence to them so far as they're concerned?"

--H. G. Wells, <em>Tono-Bungay, </em>1909

It's about a phony medicine called "Tono-Bungay" which doesn't really cure anything.

"trading" = business

"Rippin' ads" = great advertisements

"quintessence" = source

"poor devils" = victims

"straight" = honest

"How do we know it mayn't" = maybe it is

Explanation:

George's uncle: All business involves some swindling.

George: Is it honest to advertise that Tono-Bungay makes you strong?

George's uncle: Maybe it <em>does,</em> if you believe in it.

"Yes, the tremendous power of advertising is the most significant thing about modern journalism. It is advertising that has enabled the press to outdistance its old rivals, the pulpit and the platform, and thus become the chief ally of public opinion. It has also economized business by bringing the producer and consumer into more direct contact, and in many cases has actually abolished the middle man and drummer."--Commercialism and Journalism, Hamilton Holt, 1920

This humorous writer shows that a) advertisements stretch the truth, and that b) people expect them to. 

“Well, it doesn’t come up to the poster,” said George, “that’s all.”
“What poster?” asked Harris.
“The poster advertising this particular brand of cycle,” explained George. “I was looking at one on a hoarding in Sloane Street only a day or two before we started. A man was riding this make of machine, a man with a banner in his hand: he wasn’t doing any work, that was clear as daylight; he was just sitting on the thing and drinking in the air. The cycle was going of its own accord, and going well. This thing of yours leaves all the work to me. It is a lazy brute of a machine; if you don’t shove, it simply does nothing: I should complain about it, if I were you.”
--Three Men on the Bummel, Jerome K. Jerome, 1914