If you want to install Oracle SQL Developer on your Windows computer for free, check if you meet the requirements and then go through the instructions mentioned here.

The aim of this directory is to create an SQL course for all relational databases, with respect to their syntax, to serve as a one-stop solution for future SQL reference. - srijan90/SQL-Hello-World ...

Presumably this is your first installation, so 'no' would be an acceptable answer. Next you'll be asked to select the file types for SQL developer. I selected them all: At this point, you'll be ...