From the terminal (or SSH):
mkdir /home/pi/.config/autostart
Create the config file and enter the following:
nano /home/pi/.config/autostart/kiosk.desktop
[Desktop Entry]
Type=Application
Name=Kiosk
Exec=/home/pi/kiosk.sh
X-GNOME-Autostart-enabled=true
Create the script the Pi will run at start-up:
nano /home/pi/