Complete exercizes in all of these sections (https://www.w3resource.com/sql-exercises/sql-retrieve-from-table.php):
Retrieve data from tables
Boolean and Relational Operators
Wildcard and Special operators
Aggregate Functions
Formatting query output
Query on Multiple Tables
SQL JOINS
SUBQUERIES
FILTERING and SORTING on HR Database
SUBQUERIES on HR Database J
OINS on HR Database
SQL UNION
Submit screenshots with YOUR (not copy/paste from solutuions) answers.