You can indeed study the course material by yourself; I did that myself and got the (CCNA) certification. If you intent to go through it for the sake of learni

You can indeed study the course material by yourself; I did that myself and got the (CCNA) certification. If you intent to go through it for the sake of learning the just get a book, Packet Tracer or any other emulator and have fun. If you intent to take the exam as well, you have to do it a bit structured and use multiple resources. For example, I started out with Todd Lammle's CCNA book, completed it and aced the practice questions. Luckily I also went on to use other resources, (mainly CBT nuggets) since the actual exam was considerably harder than what Lammle leads to you to believe.