note does not quit-hung up

for some documentation, i opened a new note on my newly purchased imac; as soon as i wrote few words, it abruptly stopped, the color wheel replaced the mouse cursor; it hung.

now i cant quit that specific note; i cant backspace delete it; i cant quit it; even if i force quit that note, it appears again when i open the note next time.

the irritating portion is when all this happens, the color wheel is rotating, the mac is hung for initial minutes; i can perform other operations, only after a while; its bugging me.

please explain the steps to delete that weed note, that stupid note that reopens everytime, and doesnt quit.

...and this for a system, which is new. (sic)

(P.S.- there is another issue inside mac; the screen has reddish brownish smudges at the top right & top center of the screen. i am going out tomoro to replace the screen. yet, these things shoudnt happen.)