I personally wouldn't get the 250. I think you have the right idea to start with a bike with less of a learning curve but that's shooting a little low. The power of the 250 is going to get old real quick and then you are going to be looking to dump it and buy something else. I wouldn't feel safe on a 250 on the interstate at all. No guts to get out of the way if needed.
I would get either the ex500 that has been recommended here or maybe even the SV650, but if you look in the used market, there are so many bikes under the 600cc range that can be had cheap.
I've ridden my entire life and have been lucky with no major accidents. It's not a matter of if you have one, its when. Get yourself into a motorcycle safety class immediately and ride defensively.
When you come to a stop where cars will be pulling up behind you, keep the bike in gear and position yourself to where you can get out if the person behind you doesn't stop. I know a guy that was hit from behind sitting at a stoplight and is now paralyzed. He wasn't watching the car pull up and she sandwiched him between her car and the car in front of him. Had he been watching her and put himself in the lane where he could get away, it wouldn't have happened.
The best advice I can give you to stay alive on two wheels is everytime you swing your leg over that bike, get it in your head that you are invisible when you are on it. People will not see you and pull out in front of you... approach each intersection carefully and assume they dont see you.
Please at least wear a helmet... ATGATT (all the gear all the time). Reach down and feel the knot on the side of your ankle... that wont feel good grinding down the pavement, buy some boots. Gloves protect your hands and keep skin from rubbing off if you crash.... you always put your hands down first when you fall.
I had some Harley guy at the post office say "aren't you hot in that...?" as he looked me over on a pair of boots, armor lined pants and jacket and holding a helmet with my gloves in it on a 85 degree day and I replied "yes, but it feels better than my flesh scraping down the highway when a soccer mom on a cell pulls out in front of me". He didn't know what to say after that and just nodded.
When you get a bike, take it to an open parking lot and practice defensive maneuvers. Get used to how your bike feels when you have to grab everybit of brake you can without locking the wheels. I ran up on a group of about 30 wild turkeys standing in the middle of a rural road on the way to work one morning and found out real quick how easy it was to lock the wheels on my new BMW R1150R a few years ago. Thank God I was able to keep it upright but I wasn't prepared because I hadn't practiced the differences in the brakes going from a Ducati to this bike. The Ducati's rear brake was worthless and the BMW would lockup with the slightest jab of the pedal. Had I practiced in a parking lot or on my street, I would have known and wouldn't have had to right to stay up.
Teach yourself not to target affixiate (google it if you have to), ride smart, wear the gear and you'll live to tell about it. IrishBryan wont have to scrape you up off the road... :wink: