I want to make it so when it press the windows key on my keyboard the applications menu pops up. How do i do this?
To set the Windows key use:
gsettings set org.gnome.desktop.wm.keybindings panel-main-menu "['Super_L']"
If you don't like the change (as I), you can reset it with:
gsettings reset org.gnome.desktop.wm.keybindings panel-main-menu
I recommend you to check this tutorial, it has some neat tweaks for Loki.