Selecting a module for learning will totally depend on your academic background or educational, work experience in a specific domain and most importantly your interest.
As for example :
- If you are an MBA (Operations Management) graduate, then you should select the MM module.
- And if you are an MBA (Marketing) graduate, then you should go with SD.
- If you are working in purchase or procurement, operations or supply chain then select MM module.
- SD is a recommended module for a person working in the sales or marketing department.
So, before selecting any module, google it and read about that particular module. Try to find out your level of interest in the topics. Based on all these factors select MM or SD. SAP MM and SD both are core functional modules in SAP.
Want to learn SAP MM from scratch! Have a look at this right video on SAP MM provided by Intellipaat:
If you are more into reading, then do check out this material provided by Intellipaat: