Without exaggeration, the Cambridge CELTA is recognised almost everywhere in the world as the pre-requisite English language teaching certificate.
There may be countries I’m not aware of with exceptions (let me know in the comments!) but every single private language school I have read about requires a CELTA before they will put you in front of students. Many CELTA graduates are able to travel the world, finding work wherever they go, although this nomadic lifestyle doesn’t suit everyone.
There is one important exception that you should be aware of. Many countries require an additional qualification for you to teach in public/state schools. This is often a degree or PGCE equivalent.
If you want to progress further with your TEFL career, the CELTA (plus a little experience) will give you access to the next tier of qualifications such as the Cambridge DELTA.