Hi @former_member147704 ,
If you want to get an overview of what SAP does, try the Discovering End-to-End Business Processes for the Intelligent Enterprise learning journey.
If you want to dive right into specific financial accounting learning paths, you can start for free with Outlining the Finance Overview in SAP S/4HANA.
From there, the certification paths generally require a paid subscription. You can browse them here. Specifically SAP Certified Application Associate - SAP S/4HANA Cloud, public edition - Finance may be one to consider.
As a beginner, I found your response to this question very useful. I started the free course Outlining the Finance Overview in SAP S/4HANA. I would like to follow and practice each step. Please, how can I download and install Fiori Post General Journal Entries App on my laptop? Thank you!