Setting up Xtream UI from scratch requires a clean server (VPS or dedicated) with Ubuntu 20.04. Start by updating your system with apt update && apt upgrade. Then install required dependencies like Apache, MySQL, PHP 7.4, FFmpeg, and NGINX. Clone the Xtream UI installer from the GitHub mirror and run the install script. Ensure ports 25461 and 25500 are open. After install, change default passwords, configure your streams, and add your DNS under server settings. Always harden SSH, limit root access, and consider setting up a firewall like UFW for basic protection.