Students majoring in mathematics are more likely to get "scholarships" when they study in the United States. As long as you have a solid foundation in mathematics, you will soon find a job without tuition in t a after entering the graduate school of an American university. From correcting professors' homework to teaching undergraduates mathematics, you will work for professors while studying, which will be the whole of your study abroad life.
You must take GRE and TOEFL, and pass English, which is enough.
Wish you success!