THE FACT ABOUT MUHARRAM THAT NO ONE IS SUGGESTING

Did the occasions of Karbala truly happen, and if so How come we not mention this celebration and the massacre on the Prophets grandson and his little ones within our Khutbas? Also did the Prophet not point out within a Hadith that there'll be 12 successors following me? has there not been about 12 caliphs? I have already been reading about Shia Is