Understand what SQL is and why you would use it. Create and manage databases and tables. Insert, update, and delete data in tables. Use SELECT with filters (WHERE) and sorting (ORDER BY) to get data. Use JOIN to combine data from multiple tables. Use functions like SUM, AVG, and COUNT to group data and add them up. Create table relationships with foreign keys. Use SQL functions like MIN, MAX, and COUNT. Understand subqueries and indexes. Manage user permissions and data security.