Not surprisingly, tourism is a major industry in the USA for both the Government and private operators. The State and National areas are well set up and usually reasonably priced. They range from simply scenic forest drives to very large establishments such as Yellowstone National Park. Many of the Government areas record their history including many on the native people. It is impossible to list the many attractions here but be prepared for many more than you expected and a vast variety.
Private operators tend to provide attractions which have more commercial potential and the cost is usually higher for obvious reasons. There are many excellent private attractions ranging from very large show gardens to cave complexes and local township attractions.
Entry costs to attractions, etc.
Most attractions, whether they are state, national or privately owned, will have an entry charge. This will range up to $US10. If you are planning to visit a lot of National Parks and Monuments which cost typically $US10 each vehicle it may be worth buying a Golden Eagle Pass for $US50 which will give you, your vehicle and passengers unlimited entry for one year. This seems to be the only concession available to foreigners.
Senior concessions are often available for entry and for public transport so it is always worth asking. Qualification as a Senior varies quite a bit and can be as low as 55 years old up to 65 years and being a foreigner does not seem to affect this.
Shopping
The USA certainly caters for shoppers. Venues range from speciality shops to giant malls. Factory outlets are very popular and are available at a number of locations. Usually they are set up with as many as 150+ shops at the one location so it is easy to spend a whole day browsing. They seem frequently to be outside the main population areas so you will usually have a bit of a drive to get to them. Careful shoppers will find some excellent bargains here often at a third to half the Australian price. Some specials are considerably cheaper. Clothing is probably the best buy at the outlets. Check clothing sizes carefully as XL in Australia may mean M in the USA! It is best to try items on. If buying as presents it would probably help to take a couple of measurements of the people concerned.
When buying videos make sure they are PAL system videos, not the USA NTSC system unless you are sure your Australian VCR will play NTSC. Similarly camcorders on sale will usually be NTSC although some shops can supply PAL units. CDs and audio tapes are not a problem. When purchasing computer software 'bargains' make sure they will run on your software platform. For example some Windows 95 software will not run on Windows 98.
Remember too that the USA electrical system is 110 volts, 60 Hz so electrical appliances will not work in Australia unless they are dual voltage items.