hi hi, dont u guys find it really really adorable when those
kindergarten kids love u? lolx because i just resigned my job being
a teacher from the kindergarten kids and it helps me build up my
confidence and raise my level of experience. All sorts of kids i
faced when im teaching there, grumpy kids, stubborn kids, smart
kids but most of all i like those kids that give me flowers and
all. really adorable.
Now im planing to teach primary school kids then move onto
secondary school kids. I'm now 20 btw. So this got me curious, is
20 enough to teach secondary school kids? because with my recent
experience teaching those kindergarten kids. I think im ready for
the next level of the new age xD
You can try asking the homework forum, a lot of former and
current teachers. 
There are teachers as young as 21, though some of them do not
have a good time dealing with sec school students. This is
especially true for those who enter classes with students who
misbehaves very badly, are bigger than them, and only a few years
younger than they are.
Anyway, when you enter NIE, you will have to choose between Pri
Track and Sec track. That means you either teach in the pri schools
or the sec schools. In the past, there is such a thing known as
dual-trained teacher, but I don't think such programs exist
now.
If you want to apply for the degree program, get ready for the
'A'-lvl result release next year. If you want to enter the dip
program, you can apply now.