The measurable range depends on the sensitivity and for this chip, as datasheet says, it can be ±245 / 500 / 2000 degrees per second.
The absolute angle is not possible to compute using a gyro only. Gyro gives angular velocity at the moment and the measurements drift slightly with time, so a simple integration would not help either.
You need an IMU for this: a complex of gyro, accelerometer (that gives pitch and roll), and a magnetometer (if you’d like to know the yaw angle). The process of conversion from the raw IMU data to the yaw/pitch/roll Euler enagles is not trivial. Google for Madgwick Filter to get the idea. There’s no such node in XOD stdlib.