my aim is to become a civil engineer? means which subject i want to take please guide my career

Thankyou for the question.

Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including works like roads, bridges, canals, dams, and building.

Please refer to the link below for the semester wise syllabus list :
http://www.aboutcivil.org/civil-engineering-syllabus-courses.html

All the best

In high school you want to take high level math and chemistry and physics to prepare for college.
In college all civil engineers take a fixed program in calculus, chemistry, physics, hydraulics, materials, water, wastewater, soils, transportation. You want to experience all areas of civil engineering.
In grad school you can further focus on a single area say to be a structural engineer.

After a general civil engineer degree I went to grad school to specialize in water and wastewater environmental engineering.