I carry two Camelbak water bottles when I ride (filled with Gatorade). They're 22 oz, and they have a straw inside and a bite valve, so they're easier to drink from while riding--you don't have to tilt your head way back or grip the bottle in a funky way to squirt it into your mouth.
If you ride only during the day, I'd skip the front light. Make sure the rear light is very bright and has a flashing pattern (more attention-getting). The more random the pattern, the better.
I'd get an under-seat wedge pack, and in addition to a patch kit, carry an extra tube. Change to the new tube on the road, but patch the one with the hole at home. Keep the spare tube in it's box when it's in your seat pack so that it doesn't get punctured prematurely by other items in the pack.
Get a multi-tool. There's nothing worse than something loosening up on your bike with no way to readjust it and tighten it when you're miles from home. You're either stuck riding that way (which could cause an injury), or having to call someone to pick you up.
Have fun and be safe riding!