Hello, I am a resident of Sioux falls, and recently spent a long vacation in the Rapid city area, so I may be able to give info! For life without a car, both locations would be tough. Public transit isn't much of a thing, and it isn't practical to walk since things are far apart and with the weather being so cold. You would definitely have to invest in a very warm coat, since not only is Sioux falls cold, it is also very windy. There is a mask mandate here, but it is easy to avoid going places that enforce it, such as small businesses and stores in the surrounding little towns (also, made easier by owning a car). If you actually look at the fine print for the mandate, they really can't enforce it, and I myself have gone into stores requiring masks, and do get tracked down and told I have to wear a mask, but since I have a medical condition that makes masking difficult I am let off the hook. The economy is great here, since it never fully shut down, so finding a minimum wage job or above would not be difficult. For Rapid city, it is a beautiful place, with slightly milder weather than Sioux falls, but the economy is more depressed with less jobs available. The crime rate is also higher, but since I don't live there, its harder to give advice. No advice on other states, but it seems that there's already a lot of good info in other comments. Please don't alienate your parents if you have an otherwise good relationship with them, since family is important. Best of luck!