In Germany, there a several characteristics which only exist in youth language. First of all the vocabulary partly is different, words like “Digga(h)” (bro) were introduced into German by youth language and have now partly become widespread terms. But there still are specific words only younger people use and these words constantly change while only a minority stays part of the German (youth) language. On the other hand there are some words which already exist in German but are more widespread in youth language, for example the North German greeting “Moin”. The gramma also partly differs since the youth language tends to accelerate the process of language simplification. There are also exeptions for that. The youth language is influenzed by different actors. First of all probably by other languages like English (many, many anglicisms) or Turkish. But also by people who are known among young people and by more complex structures. All these characteristics differ from region to region and only a minority actually applies to the whole of Germany.
Which country are you in? Are there any characteristics of your country’s youth language? Does the youth language maybe differ from city to city? How did it change over the time? By what is your youth language influenzed?
One big thing I notice is that the youngest speakers all use [ɹ̈] for “r”, instead of the more traditional [ɹ], which means it’s formed in the back of the mouth now. I have to think that will change the trajectory of the whole phonology going forwards if it holds up, since dropping front-of-the-mouth r is a major tendency English has had.
Use of “like” as a hedge is the most famous change for young speakers all over the Anglosphere. It’s just handy, honestly, to have a quick way of conveying degrees of certainty in this highly complicated world. If future English grew that into a full mood system it would actually be great. At the other end, the last vestiges of grammatical gender have been on their way out for centuries, and are leaving at an accelerated rate now.
I think young people are much more comfortable verbing nouns than older generations. English is noted for doing this, but usually the words that can be used either way are fixed. In the absence of a better verb I’ll often improvise one, and be understood no problem by speakers my age, but I’ve never heard an older speaker do this.