Question about Hebrew before modern Hebrew

I’ve been seeing a lot of Tik tok conspiracy stuff (I don’t enjoy them I always skip ) but it said modern Hebrew was created until the 19th century and with Zionist. Is this true and if it is I have another question What prayers were we using during the shema or something else is it old Hebrew how have Torah scrolls changed with it. And if they are different I’m guessing it’s from sages who know old Hebrew ? Just found it interesting people like to debate with since I’m a Jew and like to have something to back up especially when they say our texts have been changed or something thank you