Red-lined my engine by accident

I red-lined my car on accident. I thought i was in drive, but was in second gear. I drove 60-70 mph in second gear. I noticed the loud engine and pulled over and put in in drive after five minutes of driving. I just bought the car today so I was not exactly sure how the car should sound normally. After putting it back in drive the car would turn off when trying to switch to drive from park. I finally gave it gas and the car went somewhere. While driving like this i heard something under the car. Could have been me running over something or maybe it was something more. I do not know.