Ensure you start to learn in the following order:
Step 1: Learn what is database and what is SQL?
Step 2: Learn what is DBMS and what is SQL Server?
Step 3: Learn basics of SQL Server and T-SQL Queries
Step 4: Learn Routine / Common SQL DBA Activities
Step 5: Learn Maintenance DBA Activities
Step 6: Learn Emergency DBA Activities
Step 7: Implement all above concepts in your PC ++ in on a Remote Sandbox provided in your Training Organization
Step 8: Learn and Implement / Simulate common errors and solutions that come in Real-time. There are POCs for various common errors and solutions. These are very much expected in almost every interview
Step 9: Attend minimum of FOUR to FIVE Mock Interviews from your trainining Institute.