Here are the minimum requirement of the operating system.

• Ubuntu Minimal EmulationStation: At least 4 GB is recommended.

To insert a memory card into your computer, you need a memory card reader to work with that.

You can purchase OS preinstalled microSD cards from https://www.hardkernel.com/product-category/memories/.

When you choose a memory card, please keep in mind that you should check the product name carefully to choose a proper memory card for your board.

https://dn.odroid.com/RK3326/ODROID-GO-Advance/Ubuntu/

You can easily flash an image to your memory card using Etcher.

Download Etcher here: https://www.balena.io/etcher/

1. Open Etcher.
2. Select the downloaded OS image.
3. Select the inserted memory card. (Normally, the memory card is detected automatically.)
4. Click Flash!