You have an "SPI" OLED. The sketch (and sometimes the library) will show the I/O pins... so post your sketch here (or inspect it yourself).
Here is an example of part of a sketch using an SPI OLED...
// Declaration for SSD1306 display connected using software SPI (default case):
//#define OLED_MOSI 9
//#define OLED_CLK 10
//#define OLED_DC 11
//#define OLED_CS 12
//#define OLED_RESET 13
//Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT,
From this page
GND is the ground pin.
VCC is the power supply for the display, which we connect to the 5V pin on the Arduino.
CLK / D0 is the SPI Clock pin. It’s an input to the chip.
MOSI / D1 is the Serial Data In pin, for data sent from your microcontroller to the display.
RES (Reset) pin resets the internal buffer of the OLED driver.
DC (Data/Command) is used by the library to separate the commands (such as setting the cursor to a specific location, clearing the screen, etc.) from the data.
CS is the Chip Select pin.
And I guess...
BL is BackLight or "anode"