It really depends on what kind of attack it is and who is attacking.
If Hawaii is attacked by North Korea, it will be at most a handful of poorly-aimed, low or medium yield warheads, in which case your biggest worry is fallout and wind direction, as you will most likely be outside of any major blast areas. Get under cover and try not to be looking out windows. North Korea will very quickly cease to be a threat after that for various reasons. This will be roughly the equivalent of the US nuclear attacks on Japan. Those unfortunate enough to live in blast areas will suffer horribly, but the State of Hawaii overall will ride it out and rebuild, as Japan did.
If, on the other hand, it's a full-blown exchange over the North Pole with megaton-yield MIRVs, things are different. I live close enough to DC to get vaporized, hopefully quick and painless. If you are in an area that avoids this treatment, you will need to have a short term plan for avoiding fallout for the next few weeks at least, followed by a long-term plan for not starving to death in the next few months and years. The US produces a LOT of food, and that will stop. Also, the climate will be wrecked by the nuclear winter effect, which means more than just cold and crop death, it also means UV damage and more crop death, etc. There will be no electric grid, virtually no fuel or oil production, just basically hell and then worse than hell. It is estimated that most of the world's population will survive the initial nuclear exchange, but a large fraction of the human race will starve to death within a few years. Good luck not being one of them.