Slo,
Regarding riding the interstate, there is one piece of advice that applies everywhere... Ride like you are invisible. Do not count on anyone to see you. Stay out of blind spots and if you pass someone, car or truck, do not waste any time in their slip stream.
Regarding what to take... a 250 mile ride is really nothing to worry about. It's not like you're crossing the plains in a covered wagon. There is only such a very small chance of any trouble in that short distance. Make sure you have a cell phone to call for help and a credit card to pay for it when it gets there. Generally, in the Eastern half of the US, there is a gas station every 150 yards or so.
On my first real long distance ride, I rode my FZ1 from Ohio to Nevada and back in 2004 on the 'scenic' route... 5,300 miles round trip in 16 days. I lugged along enough manuals, tools, spare bulbs, fuses, patch kits, compressors, spare bolts, chain links and miscellaneous parts to rebuild the bike if necessary. Guess what. The only tool I needed was a pair of pliers to help a teen on a dirt bike wire up his jerry-rigged fuel line. Since then, I travel much lighter.