Can i install a third seat somehow into a corvette?
I don't think you need to buy a Corvette.
If your wanting a sports car go for a Camaro, Mustang, or Trans Am. They have a backseat for more people and they have trunks. You can also modify them to go faster.
Of course if this is your first car, I'm going to guess that your a teenager, or at least very young. Maybe speed shouldn't be your top priority at this point, just function.