How long should we leave a hair dye in the hair to obtain maximum results?

My advice is to follow the manufacturer’s instructions. If you have no experience and you don’t follow the instructions, the results may be something that you are unable to fix.

I agree with @jca. Do the strand test beforehand to see the effect on a small piece of your hair.

If you don’t like the warm tones that could go yellow or brassy then go for a cooler shade. Often these are called ash rather than golden or honey.

Simply follow the directions on the packaging.
Buy the color you want to achieve, and follow the directions.