If you have to ask the question, you aren't ready to be certified.
You are not going to get quick answers to your question. Your only option is to spend some time learning the trade. This can be done partially through reading relevant books and technical mags. You will find that real experience is the best and only TRUE teacher.
Specifically to your question ... It should be sufficient for you to read what QAI has on their website regarding qualification for the CSTE. If you don't meet those criteria now, figure out what you need to do to meet them in the future.