getting a job

[milesy]

i am nearly sixteen and would like to get a saturday job when will i receive my national insurance number

[acw]

http://www.dwp.gov.uk/lifeevent/benefits/ni_number.asp

You can apply for one - the details can be found via that link.  Some people get it when they're approaching their 16th, others within a few weeks or months.  Good luck.