Primary school for a 5 yr old

[MK33]

Hi all,
This is my first post at "health, edu and family" section.
We have applied for residency and (fingers crossed) if everything goes well, we will be there in NZ by the end of next year.
We haven't yet decided where to live but would prefer CHCH if I can find a job there.
We have a boy who will complete 5 next year (DoB -3 Nov, 2007). We wish to know if we need to get him to a kindy before a primary school OR he can directly join primary school.
Our kid is not that good in speaking/ understanding English as we don't speak in English at our home.
He is learning English now. We will try to teach him as much as we can in this year.
I wish to know if he will have difficulties in school in a level that he might not me able to cop?
I wish to hear from people with similar experience.
Also, I wish to know what is the normal age for primary school enrollment? and when does the session for primary school starts?

Many Thanks