"How do I learn embedded systems programming?" is like asking, "How do I learn development?" but in an alternate universe where 128k is still a lot of RAM.
There are a lot of how-to's online for setting up a Raspberry Pi without monitor or keyboard, but none of them are simple or straightforward. This will be.
Optimize EEPROM/Flash writes across multiple pages, with multiple regions and handles wrap-around. I recently came up with an algorithm that handles this.