Will driving a couple of miles with emergency break on mess up the car?

You should be fine. It sounds like the emergency brake wasn't fully applied. If it was, you would have known it by the vehicle not wanting to move when you tried to accelerate. I'm assuming you didn't see any smoke and the wheel wasn't glowing red hot. Just keep an eye on it for a few days. If you hear, smell, or feel anything strange have it checked out. But it sounds like you're ok. Hope that helps! Jim

With how weak park brakes are today I doubt you did any powertrain damage, but you could have ruined a set of park brake lining and may a set of rotor/drum combos.