Table of Contents
Download Raspberry Pi OS
First of all, we should download the current Raspberry Pi OS version with 64-bit support. For example on the page .
The download looks something like this, depending on the current version:

If you have downloaded a ZIP file, you can now unzip it to a folder of your choice.

Raspberry Pi Imager to set up Raspberry Pi OS (64-Bit)
The Raspberry Pi Imager you need to run the operating system on your SD card to play. This does not even have to be very large if you plan to connect an external hard drive to the 3.0 USB hub anyway (preferably an SSD). The Raspberry Pi Imager you can download it here: https://www.raspberrypi.org/software/

In the Raspberry Pi Imager program you then select “Use Custom” to select the image file (.img), Raspberry Pi OS (64-bit).

Your SD card for the Raspberry Pi 3 or 4 is usually a microSD card.

As soon as you have selected the image file for Raspberry Pi OS (64-bit) and selected your SD card, you can start the writing process.

The program then checks whether the writing result is OK.

The process is completed with a message and the SD card is ejected.

Allow SSH access on Raspberry Pi OS
Unplug the SD card from the PC and insert it again. We also save a file called SSH (without file extension) on the SD card so that we can continue after connecting to our network via SSH access.

To do this, we open the Windows standard editor and click on “Save as”. Then we navigate to the storage location of the SD card and enter SSH as the file name. It is important to change the file type to “All files (*. *)”. Then confirm with the “Save” command button. Now the SD card can finally be unplugged and then inserted into the Raspberry Pi 3 or 4.
Now the Raspberry Pi should be connected to the router with a LAN cable, e.g. to your FritzBox. They should also plug in the power cord. You can then see which IP address the Raspberry Pi is running with in the router under the Network item.
Use putty for SSH access
SSH access would now have to be done, for example, with the free program Putty (for download, see https://www.putty.org/ ) function.

Enter the IP address of your Raspberry Pi under the “Host Name” field. You can start the session with the “Open” command button. At the beginning the username is usually “pi” and the password “raspberry”. For example, here you can see how you can change your username and password after logging in for the first time: https://www.elektronik-kompendium.de/sites/raspberry-pi/2109021.htm
Web development on the Raspberry Pi
If you want to develop websites on your Raspberry Pi OS (64-bit) using a PHP framework, check out this post: