The question isn't how old you should be, it's whether or not you're married yet! Sex should wait until marriage.
Yes. WAY too young. You should want to save yourself for your future husband. The bible tells us to wait until marriage.
Christians can eat anything basically. I don't believe that there are any foods that are off limits, that I know of, and I've been a christian for 7 years. =-) Have a blessed day!