Learn how to assemble, install and customize retropie to build a home emulation console.full course
After you assemble the raspberry pi kit you’ll need to flash the retropie image onto the SD card.
Install raspberry pi imager and run the application. You should see a screen like this:
From choose OS choose emulation and game OS
Choose the version for the pi you have (most likely 4)
Insert your SD card into your USB adapter and install it into a USB port on your computer. In the Imager app, click
Choose SD Card. Pick your SD card that you just plugged in.
Confirm the next screen
It should take several minutes to write and verify the image.
When you get the message that the writing is complete and can remove the SC card do so. Then put the SD card into your pi and get ready to power it up.