Hi Young
Gootta, wanna, gotta, ain't, kinda, gotcha..are frequently used in speech in informal colloquial English, especially American English but are rarely in their written form. But I doubt that outside the USA and American schools, these forms are taught to children at all. Can't see Prince Harry's kids speaking that way :) nor any educated people around the world using them at all if not for a joke.
It is, of course, important to recognise and understand them considering that are often used in song lyrics even in Britain for their softer sound (Beatles Docet) in social medias and booming because of the Netlix "generation" watching all the American series.
But again in Business Meetings, colleges and Universities outside the US these forms are rarely heard or taught if Americans are not present.
So I would maybe touch upon this topic to older kids/teenagers that watch TV series, use internet, media but I would also remind them that they are extremely informal..but there again, I am maybe too British English biased, sorry American friends! ;)