Okay to study in US you must have to give Sat first and then toefl exam to get seat at reputed University 

You should have prepared for SAT exams earlier and TOEFL too.
Planning education abroad after school is not that easy.

Most Universities in abroad welcome students from other countries for M.S. and doctorates. It is too hard to enter a UG course abroad.

My personal suggestion is to complete U.G. in your country, get some exposure and decide whether to go abroad for higher studies. Hope these are useful.

Give sat papers and get around 2400 for fud marks