Having a TEFL certificate is certainly a plus, but not a guarantee. Have a look at the job postings here on TEFL Net, so you can have a better idea what qualifications are generally required. Of course, you will have to keep in mind that these are mostly positions at private language schools or universities. I can assure you, that in the non-profit side of the ESL teaching world, which is often referred to as ESOL, the requirements are less stringent. If you don't have a Bachelor's degree and/or are not a native speaker, you might find that looking into adult community programs yields more and quicker results for your job search than doing the same in the private sector. Adult community programs are great places to start your teaching career. You can build up your teaching skills and experience, and they are always in need of teachers.