What an awesome gift you got!
My only advice, if you want a bike that will last you many years... is to look for one with Shimano 105 or Ultegra components. Durace would be even better- but it's top of the line that racers generally use.
As far as material... everyone has a preference. I went with carbon, just because it's lighter.
You really just have to ride a few different bikes until you find one that you love.
The moment I got on my Specialized Tarmac Expert I KNEW it was the bike for me.
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather, to skid in broadside thoroughly used-up, totally worn out, and loudly proclaiming: WOW WHAT A RIDE!!!!"