Hi there, and welcome to the forum!
I'm from Ireland, and I've been teaching English in Spain for the past five years.
I don't think you'd have any luck in Ireland (or indeed any other country where English is the first language). The TEFL market in Ireland is very small, and the jobs tend to go to Irish people who have bags of overseas experience. There is simply no need to apply for a work visa for a non-EU citizen when they have so many of their own citizens who could do the job.
While there is plenty of work in Spain, the market - at least in the big cities - is saturated. In any case, as a non-EU citizen, you can't just come here and look for work. You'd need a visa that allowed you to work, and the chances of that happening are pretty slim. This is because EU hiring law dictates that in order to hire a non-EU citizen, employers first have to prove that there were no suitably-qualified EU citizens who could do the job. When it comes to teaching English, that's not a very likely proposition.
Finally, to maximise your chances of finding work anywhere as a non-native English-speaker, you should invest in a reputable TEFL course, such as the Cambridge Celta or the Trinity CertTESOL. Furthermore, you will need a certificate that proves your level of English, such as the IELTS, TOEFL, or one of the Cambridge exams. At the very minimum, you'd need B2 level, but realistically, employers are going to want to see at least C1. Based on what you've written above, you don't yet have that level. So if you're serious about wanting to teach English, you first need to improve your own.
Hope that helps, and if you have any other questions, please ask.