Moving abroad can complicate things.
In the UK, I think you would only need a NCFE Level 3 qualification to work with children, but to teach, you will need something more advanced. The thing with teaching qualfiications is that most would be recognised in the country they are issued, so a PGCE might help you get a teaching job abroad, but alone should not be enough.
If you want to look into the requirements for jobs involving kids, you might want to check out National Careers Service. I'm sure you're qualified for most of them, but you may need an extra qualification to secure the role you have in mind, considering a psychology degree by itself is not enough to work with kids.
Most jobs involving psychology to my knowledge require you to do a PhD (or at least a master's), which seems more expensive that it's worth. Having said that, you should be able to let you be involved with the same sort of work anywhere in the world - usually research based.
It might make things easier if you research the job requirements in the country you intend to move to.