Linux under the hood is important in how the system installs applications, configures some settings, and more, but the overall look of the computer, known as a the Graphical User Interface (GUI or UI) is controlled by the Desktop Environment. Many desktop environments for Linux means that however your system works under the hood, you can have the look and layout that you want. If you are used to a Windows platform, you can setup your Linux computer to look like that platform. If you prefer the Mac interface you can install that setup as well. If you would like to try something all together different, you can even do that with Linux. Browse the catalog of desktop environments to find a look that fits your needs.
XFCE is one of the oldest desktops for Linux created as a FOSS version of another popular desktop.
Plasma is among the first FOSS DEs, featuring a familiar layout and many options.
Cinnamon is a fork of GNOME 3 designed to keep the desktop familiar (think Windows layout).
GNOME is a very mature and advanced desktop environment that is part of an entire stack of software.