i can understand your dad's fears. if you want to try to get your dad on your side, invite him onto the site. we have a lot of good people from your area.
as for the cbr600...have you ridden a motorcycle, dirtbike, etc.? if not, a cbr600 isn't really the choice you should going for. if you have a few fairly recent years of off-road riding, it's not bad.
they aren't the best bike to learn on. they are expensive to repair in minor tip-overs. one thing i tell all new riders who are thinking about what bike to buy, picture the bike on its side.
i dropped my cbr600f2 (which was the current model back them) twice. the first time i saw it on its side i was crushed. my first bike was an old beater (i wish i knew that there was an internet back then, i would have found a smaller beater). the first two times i dropped it, it was so ugly you couldn't even notice. the last time i dumped it, it was easier to spot.
picture a pretzle with tires. however, i paid $600 for it, put $100 into it and sold what was left for $250. that's $550 down the drain for a summer of fun.
the minor spill on my f2 had $1400 worth of damage. plastic ain't cheap.
feel free to ask questions and further check out the site. and please, if you'd like you dad's approval, feel free to invite him onto the site, check things out, etc. i know you're 22, but i know i was still explain things to my dad.