Hi Shilpi and welcome to MoveToNZ.
Firstly, I don't think you can go to NZ and start up your own business either on a Work Permit or WHV. You would either need to have PR to do this or, alternatively, you could apply for a
Long Term Business Visa . You can check out what is required
here .
If you still eventually want to apply as a skilled migrant you need a minimum of 100 points. Here are some links about how the points system works in case there's something here that might help explain things better because it can be quite complicated. If you still don't understand something, please ask on here and we'll try to talk you through it.
The points system
Points indicator
Points table .
Guide to applying for PR
I would mention that, to gain extra points, your husband would need to have a relevant qualification to go with his work experience in IT. To find out if you can apply for PR you can try to find your job titles on the
Long Term Skill Shortage List as these are the particular skills that NZ is looking for.