Transcript: You usually need to provide the transcript and course description of your current university. Even, some schools will require high school transcripts for three years.
SAT Question: Most schools do not require students with certain credits to submit SAT scores. Two years of college credit is basically enough. However, it should be noted that it is difficult to generalize how many credits can be transferred. You need to check the official website of major universities and make detailed preparations. At least it should be about 2 100.
TOEFL score: If you didn't do well in the previous exam, you need to take it again. The requirements of UCLA and UCB should be at least 100+.
Generally, there are more people applying for transfer in their sophomore and junior years. If you don't change your major, you will have the opportunity to transfer some credits. A few colleges and universities also provide transfer opportunities for junior students, but only give two years of credits at most. So it's best to wait until after sophomore year, because most basic courses can be completed after transfer.
Generally speaking, transfer requires students to provide qualified language scores, TOEFL or IELTS, and the requirements of each school are different. Some American universities and colleges require students with less than a certain credit to submit SAT scores. Because the requirements of each school are different, students should read the requirements of the school for transfer students in detail before applying for transfer, and make preparations as soon as possible.