Why must i learn English? USA!

Honestly, i need a long period of time to be an expert in one particular language. For example, i have used 13 years to get A2 for my Chinese Language in SPM. Mandarin is my mother-tongue, but i am still not an expert for this language. How about English? Will i use the same period of time to become an expert for this globalization language? I have 3 months only to prepare for my SAT and also my TOEFL, i hope i pass the cut-off point set by JPA or PSD this year so that i can fly to USA next year.
Minimum requirement to fly after ADFP,
SAT>1300
TOEFL>100
GCPA>3.5
Get a place in one of Ivy League or Ivy League Standard Universities!
Is that possible?
Think positively, if i can't fly after ADFP, i will continue my studies in INTEC by doing ACTP.
After that, more linear requirements are needed to fly after ACTP.
SAT>1000
TOEFL>79
GCPA>2.75
but i need to get a place in such tough-to-get-in university!
My own conclusion is be an expert in English before you apply for any USA universities!
How to brush up my English?
Study, study and study.