I am new and this is my presentation :)

Hi! I am Clizia. I am 26 years old and I come from Italy. I was born in a small town in the north of Italy.

(Well done!)

Currently I'm living in Bologna.  (You can also say "Right now, I live in Bologna."  The present continuous isn't needed here.  Note the contraction "I'm" in which the "a" in "am" is taken out.)

I've lived in Bologna since for 4 years.  (With expressions of time involving "for" and "since", you'd use the present perfect continuous for verbs in which you can see someone doing something.  For others, called "non-continous verbs", use the present perfect:  "I've lived here since I was 3 years old."  See http://www.englishpage.com/verbpage/types.html for a good article.)

I love this city because it is unique.  (Or "it has its own special quality".)

It is called the city of arcades ( città dei portici ).  (Perfect!)
I work at McDonald's.

My work is on shift; I am a drive-thru attendant and a bartender at the McCafè. (You could also say "I work different shifts."  You could also use "barister" as a bartender usually serves alcoholic drinks.)
My hobbies are traveling , cooking , cosplaying and surfing the on Internet.  (Note "to surf the Internet".  What is cosplaying?)
This autumn I would like to become an au pair in the USA and I'm looking for a host family.  (Well done!  Seasons aren't capitalized.)

Nice to meet you!

(Great introduction, Clizia!)

I Am New and This is My Introduction presentation :)

Hi, I am Clizia and I am 26 years old. and I come from Italy. I was born in a small town in the north of Italy , currently I have been am living in Bologna since for 4 years, I love this unique city is unique, It is called the City of Arcades ( città dei portici ).
I am a shiftworker at Mcdonald's, my work is on shift, I am a drive thru attendant and bartender at the McCafè.
My hobbies are traveling, cooking, cosplaying and surfing on the Internet.
This Autumn I would like to become an au pair in the USA and I'am looking for a host family.

Nice to meet you.