Information about "lookit"
Solution 1:
The usage doesn’t seem to be confined to children, from: Fowler's Dictionary of Modern English Usage:
Lookit:
the colloquial AmE form lookit (first recorded in 1917), used only in the imperative, with the meaning 'Listen! or Look at (something)’:
Oh isn’t that the classiest, darlingest, little coat you ever saw! ..... Lookit the collar. - T. Dreiser 1925.
And lo, look-it there...a woman playing two machines at once. - E. Leonard 1985.
It is probably worth mentioning the apparently rising usage of the expression:
”Sure look it”:
If you study or work in Ireland for any amount of time it won’t be long before you come across this phrase. Now you may well ask what this means, and the most accurate answer we can provide is almost anything! It can be a suitable response to a question, a self-serving statement or a comment in a conversation.
“What a sunny day it turned out to be”.
“Aw, sure look it”.
(Englishstudio.com)
'Ah Sure Look It' Is Fast Becoming The Most Used Phrase In Ireland.
(lovin.ie)
Solution 2:
US slang/casual/informal. It is so far removed from standard usage that many see it as an error.
Lookit began as a corruption of the transitive verb look at, as used by Theodore Dreiser in his 1925 novel, "An American Tragedy": "Oh, do look at those sleeves. ... Lookit the collar." But the intransitive verb has a different meaning. In Philip Barry's 1939 "Philadelphia Story," the character played by Cary Grant in the movie says to Katharine Hepburn, "Lookit, Tracy, don't you think you've done enough notes for one day?"
Lookit