Thank you for your interest! You should be able to import the png file as a sprite and then slice it up however you like. The process depends on the game engine you're using but that's generally how it's done. Hope that helps you get started and good luck!
Sorry to hear about your project. If you're just starting out then I recommend watching some beginner Unity tutorials to help get you started. I can't provide additional assistance here. Best of luck to you.
