Hi, it has got two stage process for audit.
Stage 1- will be the document audit
Stage 2- Will be the factory audit, for which the factory or production facility must be running. Ideally you need to demonstrate all your activities as mentioned in your scope.
Two stages should be completed within 3 months. (May be 6, need to check with your certification body).
To get the overall certification including getting your documentation and process in place, I will say minimum 6 months preparation require before you go for Stage 1 audit.
Places to look is all relevant sections of the standards that is applicable to your scope and the ones which are not relevant can be happily avoided.