MySQL is a popular relational database system. Every app needs a way to store and retrieve data, and MySQL is a top choice for many.

1. Database Design: Understand normalization, ER diagrams, and how to structure your data efficiently.
2. SQL Queries: Master SELECT statements, JOINs, GROUP BY, and subqueries to fetch and manipulate data.
3. Indexes: Learn how to optimize queries and improve performance using indexing.
4. Stored Procedures and Triggers: Grasp how to automate repetitive tasks and respond to data changes.
5. Transactions and ACID properties: Ensure data integrity by understanding Atomicity, Consistency, Isolation, and Durability.
6. Database Security: Get familiar with user roles, permissions, and encryption to protect sensitive data.