Shoud i take a ccna course?

If there is a CCNA course at your school (or at another nearby institution to which you have access) which is properly set up with equipment, so that you get hands on experience, then I say you should go for it. If, on the other hand, you are just going to learn it out of a book or online course, you will not only have difficulty passing the exam but you will learn little of value and retain less. Learn the theory from the books by all means but do the practical as well; it's useful and fun, too.