Depending on your needs, the Linux GUI, which is available in many choices, such as GNOME, KDE, etc., is very much like the GUI in any other OS, like Windows. Except with Linux, you get to chose the GUI and can easily switch from one to another, until you find the one you like best. Some Linux GUIs are so powerful that you can customize them at the smallest level, if you choose to edit all the configuration files.
If you use Firefox or Thunderbird in Windows, they are almost identical on Linux, except a couple of commands are on different menus.
From my experience, if you do not want to use command lines in Linux, you do not have to. There are fewer and fewer things that force you to use the command line to work in Linux.
Personally, I use a mix of mouse/keyboard, GUI/CLI* in my computing, whether it is Linux or Windows. Even in Windows, there are some things that are easier to do with a command line, such as renaming a bunch of files in a directory. Granted, there are Windows utilities that allow a GUI to do the same thing, if that is your preference.
If all of your hardware is recognized by a given Linux distribution on first install, you can go through your time with Linux and potentially never use a command line. If you install software that is bleeding edge/beta on Linux, you will probably have to use the CLI. However, the same is true on Windows.
Learning to use Linux, is no different than learning to use Windows. I remember the days of the transition from DOS, BTOS, and other CLI based OSes to Windows 3.11 and Win9x back in the couple of years leading up to Y2K. The legacy applications were all character interfaces, and the new Y2K compliant replacements were GUI and Windows only. I have one colleague who tells the story of training a new user and having to take three hours to convince someone that moving the mouse on the desk will move the pointer on the screen. It all depends on your perspective.
I was anti-mouse because I am old enough that I started with keyboard only interfaces. Until I got a Windows 3.0 PC and saw the possibilities. Now I am a combination user. If I know the keyboard commands for the different menus, I can do a series of steps much faster than I can with a mouse. If the menu commands are conducive to it, I can fire away on the keyboard with one hand and click away on the mouse with the other.
The way one uses a computer is as varied as individual tastes in food, or other likes/dislikes. The beauty of Linux and other Unix-Like OSes is that they give you more than one way, and often three or four or more ways to process a given task. You may decide that Linux is not for you, but keep in mind that it does not force you to use the CLI like it did years ago.
*CLI = Command Line Interface