There are a number of ways to start an app on boot. Two of the most popular are to place the command in the /etc/rc.local file or to make an /etc/init.d script. The init.d scripts are used for system which can be started/stopped/restarted, so you probanbly don't need that.
If you're looking to set up a kiosk-style system, you'll probably want to disable the normal user login facilities. It requires a fair amount of work if you want it to work properly and securely. I'd Google for "linux kiosk". You'll probably find some good how-to's.
An IDE is no substitute for an Intelligent Developer.
You are looking for a "kiosk". Many applications have a "kiosk mode" which limits the display, for exampleFirefox Kiosk Mode. The ATM's that I've worked on physically secured the PC in a safe along with the primary display and keyboard. The keyboard and external display only became active after the PC had fully booted and the application initialized to prevent the user from entering commands or seeing the boot sequence. Depending on the keyboard you expose to the user, you may have to write hardware interrupt handlers to prevent the use of "magic keys", like CTRL-ALT-DEL and so on.