America has a pretty good history of peaceful transitions of power, and I expect that to continue. Republicans selected an asshole to represent them, and he's now lost the election. He can throw a fit with his lawyers, which will doubtlessly fail, and I fully expect Biden to take the presidency peacefully, as has happened in past American elections. That's the process at work.
People telling you that this time it's going to be a war or coup are trying to scare you. In retrospect, you will probably laugh at trump for being such a pathetically poor loser, and laugh at yourself for worrying about it.