What documents do I need to travel to the United States?

To travel to the United States, you will need a passport and a visa.

THE PASSPORT: To
obtain your passport you must: 
1) Complete the electronic form
2) Schedule an appointment for a visit on the website of the
Federal Police of your state
3) The Federal Police will specify the day/time for your
visit and verification and presentation of the original documents
4) Bring other relevant documents to issue your passport, please view the website for more details. 
Once you have your passport in hand, you will need to apply
for the entry visa to the United States. The type of visa you will request will
depend on the reason for your visit to the United States.

THE VISA:

You will have to fill out the forms and have in hands all the
documents required by the American Consulate, including the following:
1)    Form
DS-160 (the form you will fill out online)
2)    Valid
passport (and old passport if you have one)
3) The page printed with confirmation of submission of the
form
4) I-20 / or DS-2019 (Document sent to you by the
Institution you will study or sponsor your program. The
I-20 is granted for F-1 visa applicants and DS-2019 will be
granted for J-1 visa applicants. These documents MUST be submitted to the
American Consulate, along with other documents, for the application of visas. I-20
/ DS-2019 will be required to re-enter the United States every time you leave
the country. So keep it with you.
5) Proof of payment of SEVIS fee
6) Visa fee (MRV)
7) Recent Photos
8) And other relevant documents

Here is the complete list of documents for your visa type
and fee rates: https://us.usembassy.gov/visits/

 Note: I-94: When you arrive on immigration in
the United States, you will receive the I-94 form with your admission number in
the country. You must present a copy of this form to your institution as proof
of approval of your visa and admission into the country.

Note: Before planning a trip outside the United States, make
sure your I-20/DS-2019 are still valid and signed by your institution’s
international office. If you need to renew them, consult your institution’s
international office to update your I-20 / DS-2019.