Hello panda: I see this is your first post here on PC. So... welcome to PsychCentral! I hope you find PC to be of benefit.

I don't know the answers to your questions. I suspect some of this (regarding bringing medications into the country) is information you would have to get from some branch of the U.S. government such as TSA or some office that deals with immigration affairs. This is really well beyond my level of experience. But I do think it is important to clarify this so you don't run into trouble entering the country.

The rest of this is going to depend a lot on which state in the U.S. you go to & what your financial situation is. In terms of paying for visits to doctors & purchasing prescriptions, one basically has to either pay for the cost oneself, or one has to have health insurance. Health insurance is either something you purchase yourself or it is often something that is obtained through one's employer. Some people can qualify for government funded healthcare services (Medicaid) if they're low income. But eligibility for this varies from state to state. If you pay for your healthcare services yourself, you can see any doctor who is willing to see you. If you have health insurance, or qualify for Medicaid, your choices may be limited by your health insurer or by the Medicaid program.

So I suspect that, without more information as to where you're going in the U.S. & what your living situation is going to be, it will be difficult for anyone to give you very accurate information. Perhaps, however, there will be other members, here on PC, who can be of more help.