You are asking a number of interesting questions. I will try to answer a few of them as best I can. Perhaps, some of our other readers will contribute their tips as well.
The best way to get around the USA is via a combination of internal flights and car rentals. The distances across multiple states can be great, and the scenery rather tedious in some areas which can make driving long distances a real bore. Public transportation is good in the major cities, but otherwise, is poor to nonexistant. When exploring the countryside, or visiting the major attractions, a car is invaluable. Most US natives would rather take an airplane from the East Coast to the West, but then rent a car to explore the attractions in the West.
If you check the air fares across the USA, or from New York to Florida, you can often find bargain fares that are more economical than driving. You should check the airline fares at least 3 weeks in advance and compare them for the best prices. You should also check the discount airlines' web sites as they are typically not listed on the major travel booking engines. Southwest, ATA, AirTran, Frontier, Spirit and Jet Blue are a few of the discount airlines servicing internal travel in the USA.
If you stay out of the big cities, there are plenty of inexpensive motels including chains like Motel 6, Econolodge, and Comfort Inn. They typically rent a double room with two large beds (that could easily accommodate up to four people) for nearly the same price as a single room. If you are two or more traveling together, you can share an inexpensive room and keep your costs down. In the big cities, it is more difficult to find inexpensive motels, but you can search for hostels.
If you are seriously looking for a plentiful supply of beautiful women, you should go to Spring Break in Florida. The last few weeks in March is the time for "Spring Break" or the spring holidays for most colleges and universities in the USA. Hundreds of thousands of young students will migrate to the warm climate at Fort Lauderdale, Daytona and Panama City Florida. Those beach towns will turn into a frenzy of non-stop parties for several weeks. Unfortunately, the hotel rooms will be expensive and fully booked many months in advance as students attempt to cram six, eight or more friends into a single hotel room. Some students will sleep in their cars or sleep on the beach. Nearly everyone will party day and night.