can someone help me to learn punjabi?

Its just an informal way of trying to express the pronunciation, like arabs write 3 for "ain", like ya3ni or 7 for "ha", like A7med.

Capital N, represents a softer form of N, where the sound is "nasal" but does not end with tongue joining the palate for a proper N.

Punjabi is written in two forms, Pakistanis write in arabic alfabets, with some variations, while Indians write in a different way called "Gurumukhi".

As for urdu, Indians speak a different language called "hindi", which has essentially the same structure as urdu but has lot of sansikrat words, as compared to urdu which as lot of persian, Turkish and arabic words.