I am a student who just took the college entrance examination this year. My English is 132. I am a Wall Street Grade 7, and I am going to study 12. To tell the truth, the tuition is still quite expensive. Personally, I think it is better to have a certain foundation before going. Because, if your level is only Grade 2 or 3, which proves that your English foundation is not good, you should read more books and memorize more words. Wall Street mainly practices oral English and listening, and its vocabulary and grammar are limited, which is not conducive to people who have learned from the basics, and it is a bit of a waste of money.
People who have basic knowledge and want to improve their English communication skills will benefit from learning. I have a friend who studied preparatory courses in Canada for the first three months, from grade 5 to grade 9 (he tested grade 6 and sometimes suggested demotion). After going abroad, it is easy to adapt.