The best way to get Salesforce work is at a minimum to get the administrator certification.First, go to the Salesforce Certification site and read about the administrator track.Becoming a certified administrator(ADM – 201) is the first and most important step.
Second step will be analyze the syllabus for particular exam.
For any Salesforce preparation Trailhead is the most important part and doing trailhead modules the best way to crack the exam.
Here is the Link https://trailhead.salesforce.com/credentials/administratoroverview
Choose your role
Crack the exam and verify your result in offical website https://trailhead.salesforce.com/credentials/verification