Someone asked me, "How's it going, Jadoon?"
Does this mean same as "what's up, How are you, what's going on"?
Basically, yes. How are things in your life going? Is your life good/bad/indifferent? You might also be asked "How [are] you doing?" which means the same thing. If you have ever seen the TV series "Friends", you might recognise "How you doin'?" as Joey's catchphrase for trying to pick up women.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.