What happens during and after launch?
This YouTube video will take you through launch steps and deployment or this interactive guide from NASA. In short, it will be placed in an orbit around the Lagrange Point known as L2 beyond the moon, tracking Earths rotation around the sun. This journey will take about 30 Earth Days.
Calibration and testing will take about 6 months.
Potential non-YouTube live stream from ESA here: https://www.esa.int/ESA_Multimedia/ESA_Web_TV