Great job, easy to understand your meaning. I made some corrections, and capitalized them so they stand out.
Introduction
Hi everyone! My name is Nirajmehra and I am FROM India. I am 24 yearS old. My reason FOR being here on this website is to LEARN different languageS and cultureS, Especially Portuguese, English, and Spanish .These are my three FAVORITE languageS apart FROM Hindi which is also my native.I HAVE BEEN learning english FOR 3 YEARS or so and I have learnED A lot FROM these 3 years. It's has been really GREAT going THROUGHout these 3 yearS.
About my spanish and portugese experience: both these languages are really hard to me and new as well to learn but i am still practicing a lot of it.
People pls review my writing :)) and figure out what are the mistakes which I can avoid next time.