Hi,
I have tried to configure the I2C with FlexComm0 module, for the error, pls put the mouse on the error message which is located at the right-bottom of the peripheral menu, then right click the mouse, update the software file, the error will disappear.
BTW, I suppose that you can refer to the I2C example code, then copy the code to your application based on freeRtos, including pin configuration, clock configuration.

Hope it can help you
BR
XiangJun Rong