Well, if you are an SAP-certified consultant. Then, certification surely helps in shortlisting your resume. Although certification will only give you some advantage, it is not mandatory to be certified to get a job.
If you are confident enough, then you can start applying for various IT services/consulting companies like Capgemini, Accenture, IBM and depending on your country of residence others like Infosys, TCS, Wipro if you are from India. There are many organizations that have captive IT centers. It could be easier to get in the captives.
If you want to learn SAP MM from scratch, then here's the right video for you:
If you are more into reading, then do check out this material provided by Intellipaat:
You need to keep your knowledge current, bit both terms of processes (procurement, inventory management, MRP and the like) and SAP configuration.
You can use the interview questions as a guide for your subsequent interviews. Keep track of the frequently asked questions. Integration with other SAP modules FI, SD will be necessary/advantage.
Looking for frequently asked SAP MM interview questions! Here's the right material for you:
Some exposure to support processes or implementation methodology will be good. (it is unlikely to get implementation project for a fresher but methodology knowledge helps).