OK,I have very dark brown hair,and just yesterday,I dyed it honey blonde but the color turned into medium brown on my hair(:,which is not the color that I wanted.I mean I want to have light brown hair color,so how do I do that now at home?

It's almost impossibly to get a dye to really lighten dark hair. For that, you'd need to bleach it, THEN dye it the color you want. Which, by the way, I don't suggest.

Ugh,OK.but if I dye it now with another shade of blonde what will my hair color be?

There's no way to know until you try it. Nothing may happen. Your hair might come out lighter. It may turn orange or green. There's no way to know how the chemicals in the dyes will react to the natural chemicals in your hair.

Color doesn't lift color! Only bleach my dear! Or a modulate! That will result in bringing out your hairs natural underlying pigments Wich will then need to be colored with the proper color formulation to counteract those pigments! This is what salons are for! If you attempt this on your own you will end up w parts of your hair yellow orang red or even a bit of pink on the very ends! Then will need to select the right colors to deposit on each different color to result in what you want to be your target color! Please go to salon!