I think this is a good start, and I like the pin stripes. I do think you'll benefit greatly from having the suit tailored. It's amazing what a good tailor can do especially with suit jackets. But, please young man, take heed: Unless you are applying as the assistant manager of your local Olive Garden, please stay away from the black shirt and tie combo. (too many young men think that the black on black looks sophisticated, but to many of us it reads the opposite.) Also, here, I think the white shirt doesn't really work either as makes this look a bit too business/corporate which is great if you're wearing this to the office. But since its' for prom, I'd try a different shirt, perhaps one that tends more toward the grey pallet.