How to Build Dax formula

[koolsid786]

Hello All

I am new to Power BI and Preparing for PL 300 I am facing so much issues while creating DAX commands, I am not able to relate the ask and create proper DAx commands can you please assit how to learn this or how to approach creating a dax command ? 

For ex Below: 

[lbendlin]

Use Quick Measures and DAXPatterns.com to get an overview of the most frequent usage patterns for DAX.