Ordered Brick without SD card, what to do?

Dear community,

I am still waiting for my Brick, it’s still at the customs office 😬.

In order to be prepared, can you please let me know do I need to download and flash some system on SD card, which one is most stable and is there archive of SD card content somewhere online?

Also if there is something else I need to know before start playing, let me know.

Thanks! 🙏