Considering a trip to NYC, I'd like to save $ , travel quickly, and stay safe the whole time. Your suggestions?

Some friends of mine are getting married. I’ve never been to a really big city before, except for Boston. Driving there would be cheapest (I think) but parking – and not getting my car damaged or stolen could be a challenge. I could figure out a place to stay- but getting around the city has me nervous. NYC might be more than I can handle. Would you suggest any “rules” for a 1st-timer to the Big Apple?