"but unfortunately there's no I2C address mentioned in it"
That's because SD cards run on the SPI bus, not I2C.
You need connection to SCK, MISO, MOSI, and SS.
On an Uno these would be 13,12,11 and 10, or sometimes 4. Or any pin you wanted as long as 10 was declared as an output.
On the Mega, those are 52 (SCK), 50 (MISO), 51 (MOSI), and 53 (SS).
SCK, MISO, MOSI are also on the ICSP header:
1 MISO VCC 2
3 SCK MOSI 4
5 Reset GND 6