The Internet can be regarded as one of the world's most important inventions which brings numerous impacts on people's life.
.... good start but the latter part has a problem. This is my suggestion;The Internet can be regarded as one of the world's most important inventions that made the biggest impact on the lives of people.
Some people may show their show concern / have reasons
reasonsconcerns over for the negative effects broughtcaused by the Internet.
However, I personally believe that the advent of the Internet has
civilizedimpacted positively on our way of living, both physically and mentally
... "civilize" means make someone more refined in terms of socially and culturally. So it is not the appropriate word to use here.
Though you have some little issues with sentences, your introduction follows good structure :)
Firstly, the Internet brings us the physical impacts by simplifying life.
....hmmmmmm "physical impacts" sounds a bit odd.First, the Internet benefits us by offering simplified solutions to our lives.