Hmm. Yes I did this course and loved it. I don't think I'm a natural but I'm enthusiastic and prepare assiduously.
I live near a city and my satellite town has language schools. I haven't applied to them as I didn't have the confidence to do so. A friend of mine has done and got work. However, it was cover work, and she would get phoned up the night before and told to prepare for three hours of lessons. One of our trainers on Celta course said when she was teaching she wasn't told if her contract would be renewed month to month.
I ended up advertising locally on noticeboards. I set myself up as a private teacher. I got a few one to one pupils that way and some through word of mouth. I could have probably got more if I'd made more of an effort but I was also volunteering teaching refugees at a charity that met in a church hall.
So, you can get work, probably working in most geographical areas but language school work doesn't seem that secure, and is not well paid. For freelance work you have to advertise quite hard to get a small to reasonable amount of income.
Not surprisingly, many on my course were younger than me and looking to work abroad. Lots were also not native English speakers.
To sum up - great course, interesting and worthwhile job but precarious as an income source.
I'm 50 btw and did the course about 8 years ago.