sudomod

What exactly am I putting on the pi zero?

Retro Pi?

I thought I was putting that on the cartridge with the SD card?

Ive already programmed the Teensy LC with the code provided by wermy.

But what do I put on the SD card (8 gig is what I got)
then does that sd card stay in the pi and Ill need another for the cartridge?
with what on it?

Pi-zero = What ?
Cartridge = what?

I would recommend Retropie on the micro sd card that belongs to your zero.
The sd card that you see in the gb-case is just an extension to the reader on your zero.
So it's the same card =)