Fedora's default desktop environment is GNOME 3 in the Workstation spin, but it is very easy to try any of the many other desktop environments that are available without affecting your current desktop environment.
The desktop environment such as KDE, XFCE or MATE can be installed using GNOME Software or with dnf directly from the terminal
Installation
To use dnf, first find the full environment name using
dnf group list -v environment
Available environment groups: Fedora Server (server-product-environment) Fedora Workstation (workstation-product-environment) Fedora Cloud Server (cloud-server-environment) KDE Plasma Workspaces (kde-desktop-environment) Xfce Desktop (xfce-desktop-environment) LXDE Desktop (lxde-desktop-environment) Cinnamon Desktop (cinnamon-desktop-environment) LXQt Desktop (lxqt-desktop-environment) MATE Desktop (mate-desktop-environment) Sugar Desktop Environment (sugar-desktop-environment) Development and Creative Workstation (developer-workstation-environment) Web Server (web-server-environment) Infrastructure Server (infrastructure-server-environment) Basic Desktop (basic-desktop-environment) Minimal Install (minimal-environment)
For actual installation, type the following, and be sure to prefix with the @ sign
sudo dnf install @kde-desktop-environment
Switching Desktop Session
Once installed, you can switch to the new desktop simply by logging out and switching the session to the new desktop environment on the login screen. The exact method differs based on the display manager in use.