That's the cause of the garbage data. Pins 0 and 1 on the Uno are used for Serial communication with your PC over USB so you should avoid connecting anything to them. If you do connect things to them you can expect them to interfere with serial communication including uploading code to the Arduino.
Okay, thank you.
it expects you to connect the interrupt pin to pin 2 on your Uno and then uncomment the line.
So, do I choose one of the interrupts on the IMU and connect it to pin 2? Or does it have be int0 or int1?