Read “Lucifer’s Hammer “
I did. Also read “One Second After”.
I think prepping might give you a headstart, but in 2-4 weeks, you’ll be as hosed as everyone else. Those with flashy shelters will be targets, initially. After a while, desperate gangs will start targeting ANY house where there might be supplies. Trusted neighbors banding together for common defense will have the best chance.
Excellent book.