can anyone help me design a secondary distribution system for a subdivision? Sample how to compute the the number of pole and customer to be connected to the transformer?? that kind of thing...

 

You are not getting replies because you are just sitting back and waiting for someone to do all the work for you.

Response tends to be in proportion to the perceived effort on the part of the OP.

Imagine what response you might have got if you had bothered to include things like:
Size of the subdivision in terms of houses
Topography of the subdivision
Can subdivision grow over time
Kind of street lighting
Are business zones close by
Frequency and voltage to deliver
Capacity of pole pigs
Capacity of transformer farm
Nature of the power poles
Modern tendency in US is to distribute underground - why no such option?