Configuring your project structure and IntelliJ IDEA preferences/settings
You can configure your project structure as well as your preferences/settings for IntelliJ IDEA.
Configuring Project Structure
The Project Structure is where you can change your Java SDK, Language Level. and more
Configuring Preferences/Settings in IntelliJ IDEA
There are lots of ways to make IntelliJ IDEA your own.
Configuring IntelliJ IDEA with Search Everywhere
As well as the Preferences/settings dialog you can use Search Everywhere to make IntelliJ IDEA your own.
Sharing IntelliJ IDEA Settings
You can share settings across your own instances of IntelliJ IDEA or with your colleagues.
Summary - Configuring IntelliJ IDEA
Both Project Structure and Preferences/Settings provide ways to make IntelliJ IDEA your own.