NFC tag reading in python on raspberry pi

NFC tag reading in python on raspberry pi

So i bought a cheap mifare NFC chip reader from ebay for 5$. I wanted to
play around with chips, and ultimately copy some NFC chips i have here. I
have a NFC chip that I use to open my locker with on school, but the card
we have is really big and inconvient, so I want to copy it on a smaller
NFC chip and put it on my keyring.
So i hooked it up with my raspberry pi, and first off, there is NOTHING on
internet about connecting this card with your raspberry pi. Ohwell, a
challange, fun.
I found some basic code from a spanish website(im dutch so itwas kinda
hard to understand :P) but it can only read the UID of a NFC. So i tried
to understand it, and eventually i did, and I added the code to
calculateCRC and read some blocks.
However, I have no clue how the NFC data structure actually works, all i
did was find some arduino code samples that were in C, translated them to
python, and I think it works.
So i setted it up that it reads block 0 to 8 and prints themn all. On all
the NFCs i have I can only read block 0, rest is giving an error. And
block 0 consists of one byte, that's a 0x04.
If anyone has any clue what is happening, please tell me. And are there
any links were NFC data structure is actually explained. I found a bunch
of Android stuff, but i dont have a smartphone, and i want to do it with
this MFRC522 card. I read somewhere you need to auth a block or something?
I saw some code for that too, but how does that work? How do I know the
keys?
thanks