Nah, civil war won't happen, that would require the US military to completely fracture and I don't see that happening yet.
I do expect a lot of civil unrest. If Trump loses, a lot of crazies might indeed pick up arms because of course the Cheeto won't cede to truth, he doesn't give a fuck and he has crazies that somehow are willing to die for him. I expect terrorist attacks throughout the country that make January 6 seem like a Disneyland visit.
If Trump wins then things will on the one hand be quieter, but I expect them to get a LOT worse. He's already indicated that he won't take 4 years as a term (if the fat fucker lives that long anyway) and he'll happily install himself as Emperor for life. He's indicated he'll happily start jailing and killing (did i say killing? I meant accidentally oopsie-ing) opponents and basically turn the US in a defacto Christian fascist dictator state. I'm fully expecting Trump to at least try and turn the US into the handmaid's tale.