Learn in-depth about airplane operations
I'm not aware of any official resources which present all that information in a concise way, but to get a general idea of the operation of a modern civil passenger aircraft you can refer to the manuals provided with flight simulation add-ons. As opposed to the standard aircraft contained in most flight simulators, these payware models are very accurate and highly complex.

Next to the complete manuals, each aircraft typically also contains a tutorial flight manual, where all the steps necessary for the operation are shown in detail (100+ pages each). Here are a few examples:


787: http://qualitywingssim.com/files/ultimate_787_collection/docs/QualityWings%20-%20Ultimate%20787%20Collection%20Tutorial.pdf
A320: https://www.aerosoft2.de/downloads/a318-a319/Aerosoft-Airbus-A318-A319-Vol6-StepbyStep-EN.pdf
Some other Boeing aircraft (PMDG): https://www.precisionmanuals.com/pages/downloads/documentation.html


If you're specifically interested in ATC communications, you can for instance refer to the IVAO documentation about IFR phraseology: https://www.ivao.aero/training/documentation/books/DOC_IFR_phraseology.pdf

Remember that these are NOT official documents, so they are not suitable for any real world use. But in my opinion they are the easiest way to get an idea of aircraft operations. At least that's how I learned it! It has helped me a lot in my Aerospace Engineering studies.