You may need to find the Minecraft data folder for many reasons, the follwing is a guide to do so.
All Platforms — Easiest
To get to the minecraft data folder, open the Launcher and go to Launch Options. If you cannot
find Launch Options, use the disclosure bars in the upper-right hand corner beneath your
username. Select the profile you are using and click the green arrow to the right of the
Game Directory row.
This technique may not work, and you may receive a message saying: "Could not open the
game directory." If this happens, use a technique listed below.
To find the Minecraft data folder on Windows, hold down the Windows key (usually a
picture of a flag, and typically between the Control and Alt key, usually to the left of
the space bar) and then press the R key without letting go. A box should pop up, titled
Run. In that box, you need to type %appdata%\.minecraft, then click the OK button.
Triple click the line below to select it, then right click (hold control and click) and select Services
> Show in Finder
If you are unable to complete these steps, then try this: