Hi,
- Power BI Desktop also comes with Power Query Editor. Use Power Query Editor to connect to one or many data sources, shape and transform the data to meet your needs, then load that model into Power BI Desktop.
- To get to start with Power query editor select Edit Queries from the Home tab of Power BI Desktop.
- With no data connections, Power Query Editor appears as a blank pane.
If you need more information and want to work with power query editor you can look into this docs:
https://docs.microsoft.com/en-us/power-bi/desktop-query-overview
For mastering Power BI concepts, check out Power BI Training offered by Edureka.