If you're in Ontario, TEFL 1 will allow you to teach in the province. TEFL 2 allows you to teach internationally. The market is very competitive and finding a full time job here is challenging. There are far more opportunities in other countries, specifically Japan, China, and Korea. There are opportunities in Europe but they tend to get teachers from the UK due to visa requirements.
I imagine teaching English online is very competitive. That being said, with teaching a language you have to do it if you really love it, not for the money. You can make a career, and you will be most successful if you're passionate about your work and about helping your students succeed.