I am studying in 10th and I am very bad in maths. I would like to take computer science after 10th, as I’m very bad at maths. What should I do? Is maths necessary for taking computer science?

Math like any other subject requires practice and then you become good. Start by solving all the problems in your study book. You got to justify each step you do in your solutions so you will know why you are doing the step. It takes some time but with some work you can be good in math.