Which Linux distribution should I install on this ASUS Zenbook?

Linux Mint Cinnamon is probably the easiest starting point for someone new to installing Linux. It has a familiar desktop, good documentation, and tends to be stable and straightforward. Kubuntu is another good option if you prefer a more customizable desktop. Whichever one you pick, make a backup of your important files first, create the bootable USB, start the laptop from it, and follow the guided installer. If you want to keep Windows, choose the dual-boot option carefully; otherwise, selecting the option to erase the disk will remove the existing operating system.

If Ubuntu worked well for you before, using a current Ubuntu release again is a perfectly reasonable choice. Your Zenbook is modern enough that most major distributions should run, but check hardware compatibility first—especially Wi-Fi, suspend, the OLED display, and the newer Intel graphics. Download the ISO from the distribution's official website, write it to a USB flash drive with an imaging tool, then boot the laptop from that USB. You can usually try the system in a live session before installing, which lets you test the hardware without changing the SSD.

Almost any mainstream distribution should be capable of running on those specifications. Fedora KDE is a good choice if you want newer software and are comfortable troubleshooting occasionally, while Debian emphasizes stability but may ship older packages. Before committing, test the live USB for wireless networking, sound, brightness controls, touchpad gestures, sleep/wake, and graphics acceleration. Also check whether Secure Boot needs to be disabled—many distributions support it, so only change that setting if the installer or hardware requires it.