Depends on what he does. Since I'm in the least likely demographic to be targeted (hmm, unless they start going through political groups I've been a member of), probably the same as I'm doing now. If it looks like there will be a civil war, I'd probably try to leave the country, but I guess that'd be too late, and I think a civil war is unlikely. I don't think many people would be willing to give their lives for... the Democratic party? I think the U.S. will become more like Russia (fake elections in red states [ensuring the Republican party the presidency and congress forever], more brutal police oppression, erosion of rights, opposition leaders falling out of windows, and encouragement of vigilante "justice" against whoever the "enemy" is at the time). I think protests and riots would be the most people would do, and they'd likely be met with increasingly deadly force.

Since covid, I make sure I keep a few months of non-perishables and water on hand in case of temporary supply chain disruptions, and I have plenty of wood to heat or cook with if needed. If there is a severe economic downturn (which is likely to happen in the unstable environment Trump would provide), and I couldn't find another well-paying job, I'd probably lose my home for not being able to pay my mortgage though.