Hello,
I just started with all that arduino stuff and bougth a board and a display.
But my problem is that my I2C Display won't be recognized by the I2C scanner.
Arduino model: Aurduino Pro Micro
LCD Model: LCD 2004
Sketch: I2C Scanner
I tried to connect it via USB3.0 and USB2.0 but it made no difference.
Scanning...
No I2C devices found
That's how I wired it up (right click and open in new tab for bigger image):
I hope theese information are enough 
Have you selected the right board?
My guess is that you are using the incorrect pins for SCL and SDA.
My suggestion would be to use my hd44780 library package.
It includes a diagnostic sketch that will test your i2c signals and tell you which pins are the SCL and SDA pins.
You can read more about it here: GitHub - duinoWitchery/hd44780: Extensible hd44780 LCD library
Spend some time reading about the library before installing it.
Install the library using the library manager.
The i/o class that you will want is hd44780_I2Cexp.
The diag sketch is called I2CexpDiag.
The library includes many other examples for the i2c backpack class hd44780_I2Cexp.
The library has many features like automatic address and pin mapping detection so you don't need to know or configure the i2c address.
--- bill