TYPO3 v9 has reached its end-of-life September 30th, 2021 and is not maintained by the community anymore. Looking for a stable version? Use the version switch on the top left.
You can order Extended Long Term Support (ELTS) here: TYPO3 ELTS.
These are the steps you must perform:
Make sure your system is setup as described in System Requirements.
Install base system: It is recommended to use Composer for installing as described in Install TYPO3 via composer. As an alternative, you can install TYPO3 without Composer: Install TYPO3 Without Composer.
After the base installation, you must follow the steps in The Admin Tool.
Install the Introduction Package. During installation, the Introduction Package will create several example pages and content, it will configure the web site and add a website template using the Bootstrap Package.
The rest of this tutorial is based on the Introduction Package.