PowerQuery in combination with PowerPivot can handle most reporting needs and will be able to connect most db out there.

If you need more custom visuals, publish report to secure web etc... then you may want to look into PowerBI (Pro subscription, but you can start with free Desktop application).
It uses same query engine as PowerQuery and PowerPivot (with some additional features as R/Python integration, visual customization etc).

With PowerQuery, you can bring in SQL table as is with relationship column(s)/tables and transform it using GUI and M query language.
However, I'd recommend learning basics of SQL query, for performance reasons.

Some links for learning basics:
https://support.office.com/en-us/art...7-d3da689091b5
https://radacad.com/tutorial-introdu...to-power-query