The job market in Spain is reasonably good for qualified teachers. Many jobs aren't advertised online so you have to be there in person to find them - that's using the Yellow Pages and tramping the streets, knocking on doors.
But... if you're doing a TEFL course then you'll be spending money on the course itself as well as accommodation and living expenses while you're doing it and obviously you won't have the time to earn money while you're taking the course.
You don't say much about your current situation but is it possible to stay where you are and do a course locally or online and then when you're qualified to get over there? It'll work out cheaper I would suspect.
(You also don't say your nationality; if you're not from Britain or Ireland then you should forget trying to get work in Spain due to visa issues.)TEFL in Spain