(If this info is more basic than you need, apologies)
As others have said, unless Brazil has a scholarship that you are eligible for, the only nationality that is relevant for you is your US citizenship. As a US citizen you are eligible for financial aid, and the FAFSA (which is a loan program, and is limited to approx $5K/year.
There are two basic categories of college: publicly funded and privately funded. A “public” university gets money from the state to help pay it’s costs, and students who are resident of that state pay lower tuition than students who are from another state (“out of state” - OOS). A “private” university does not get money directly from the state, so the tuition is the same no matter what state the student is from.
Colleges help with the cost of attending in 3 ways: recruitment (typically sports, when you are so good at a sport that they want you to come play for them); “merit” (when you are a good enough student that they want you to come study with them) and “need” (where they cover some % of the difference between what they think that you can afford and what they usually charge). At some schools “merit” can be “stacked” (added) to “need”, in others it can’t.
Figuring out financial aid is hard work, but one thing is pretty sure: the odds are on you finding a college that will give you tuition and accommodation for $5000 are pretty near zero.
@happymomof1’s suggestion of moving to the US, establishing residency and starting college at a community college is a good one. Most state universities have ‘articulation’ agreements with the local community colleges: if you complete 2 years at the community college (with certain grades and classes) you can transfer to the state university and finish your degree there. BUT: establishing residency for education purposes is hard in many states, especially the states that have highly ranked public universities (such as California and North Carolina), so search for info on the state that you are moving to, to see what the rules are.
There are other sources of funding: private organizations provide scholarships (the Rotary organization, for example), and some governments provide scholarships for students to attend college in other countries. You mention ROTC on another thread, and it is possible to get most of college paid for, but I think the application deadlines are coming up, and it may be hard to organize from Brazil.