I am a sophomore now. What should I do if I want to study abroad (USA, Canada, etc.)? What major is better to study now, and the most important thing is to study later.

You need to prepare the language first. Generally speaking, British graduate students need IELTS 6.5 or above. I wonder how your English scores are? In view of the difficulty of IELTS test, you can attend an IELTS training class before the test. I know the century IELTS is not bad. Their general school is in Beijing, and I study in their Shijiazhuang branch. They are all taught in small classes with no more than 15 students, and the teachers are very responsible. You can go and have a look. I know Shijiazhuang Branch is located in Fubang Building, No.523 North Street.