Kelly Broekstra recommends against jumping right in:
Who has been told by a manager or business person to just connect to the source data and start creating a new report? Here is my tip:
DON’T DO IT
All Power BI and Fabric reports must have a semantic model, which Microsoft describes as “a logical description of an analytical domain, with metrics, business-friendly terminology, and representation, to enable deeper analysis.” – Source
Read on to learn why and what you should instead do if you want to have a better long-term experience with Power BI.