If your Dad's bike fits you well, you would have to spend a lot of money to find a 2006 bike that is a nicer ride.

A road bike DOES handle, shift, and brake differently than a mountain bike. You might want to spend an hour or two in a large empty parking lot, practiciing handling the bike at different speeds, until you can do an "obstacle course" easily. Practice braking until you can do a "hard" brake manuever smoothly, without locking up the front wheel or skidding. Turning, avoiding obstacles, shifting, and braking should be natural and "thought free".

At that point, you will be ready to get out on the roads where you will be surrounding by three ton vehicles driven by the thoughtless, the brain-dead, and the homicidal. Make your mistakes in an empty parking lot, not at a busy intersection full of cars going 40 mph.

The more you practice, the easier and more natural riding a road bike will be. The more often you ride, the more fun you will have...and having fun is the best reason to ride.