Hello,

Mathematics is a important part is the exam and it is one of the difficult part as questions asked are tricky. You can do it. Firstly solve NCERT maths 1 and 2. You can get NCERT 12 th 1st year and 2nd year solution in the web. NCERT is most important. If you have any doubt then you can ask your teacher or even look online. Youtube is a very good scource and you can understand it very well but First reach to teacher and for more clarity you can watch it from youtube.

For online course, you will only get material but no will be give you a course for free. You can only get solutions for your questions.

Better to ask your own teacher as they will make you understand why the question is solved in that way and what scenario the formula is used. For more question you can prefer arihant or other math books.

Take time ,have patience and even you are not able to solve , it's okay. Try to do it again.

Hope it helps!