2nd I2C bus on CubeCell HT-CC AB02 board

I need to connect a sensor to CubeCell board via I2C bus. Based on the schematics, I believe the onboard SH1107 OLED communicate with the MCU via I2C_SDA and I2C_SCL pins (#40 & #39).
Therefore, I cannot use these two pins to connect to the sensors.

There is a 2nd set of I2C pins (#37 GP9 & #36 GP8) based on the pin diagram

My question: what is the I2C address of the 1st and 2nd set of I2C bus?

If you use the second set of IIC, you can use Wire1.begin();

yes you can, thats the good of i2c! what you need is just to know the address of your sensor. each i2c device has it’s own address, in this way you can send ON THE SAME SCL and SDA lines commands to the display OR to your sensor just indicating the right device address.

usually you have a ready-to-use library for your device wich already knows the correct address, but sometimes you can set it in the begin method.

have a look here: https://www.youtube.com/watch?v=QQLfzlPGjjE