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You cannot learn MM just by watching videos. MM is a transactional module; you must create a PO, post a GR, and see the accounting impact. Free system access is the Achilles' heel of the free movement. SAP offers a Trial System on SAP Cloud Appliance Library (CAL), but it is often limited to 30 days or specific use cases. The "freemium" model here is stark: you can learn the theory of vendor evaluation for free, but to practice configuring valuation classes or setting up release strategies for POs, you typically need a paid sandbox. However, the determined learner can use SAP Learning Hub, edition for SAP S/4HANA (90-day trial) or partner demo systems to gain short-term, hands-on access without paying the full license fee. sap s4 hana mm training free
SAP maintains a public demo system that requires no installation. This is your best resource for "how-to" click-by-click