What are the general requirements necessary for getting into US colleges? is there like an entrance exam to be written?
It looks like you are an international applicant.
Each college and university in the US had its own admission requirements, and puts that information on its website. Some require that you submit scores from standardized exams (the ACT and SAT). Most require international applicants to provide proof of proficiency in English, and might require the TOEFL or another exam.
You can look for basic information here: https://educationusa.state.gov/
What country are you from?
What’s your parents’ budget?
Have you heard of SAT, ACT, TOEFL/IELTS?
Anyone can apply but to actually attend, your family must be able to cover the net costs for all 4 years (after financial aid, if any). Otherwise, you won’t get a visa to study in the USA.
It can vary by school, but in general, the requirements are:
High school transcripts
TOEFL (English language exam)
Perhaps SAT or ACT
MONEY. (A lot of it.)