• If possible, make a DHCP reservation for your new server. This simplifies the network configuration on your server and
• If possible, register a DNS name for your new server and point it to the assigned IP address. The installer will ask you for the FQDN, so it saves time if you set it correct from the start and don't need to change it afterwards.

First, download the latest version of Debian from https://www.debian.org/distrib/. I recommend downloading a complete installation image as nowadays, it easily fits on a DVD or USB thumbdrive.

Then, write the image to a DVD or USB drive and boot your server from it. You may need to access the boot menu or BIOS to do so. On amd64