It might do you some good to familiarize yourself with Linux. Grab an ISO of Ubuntu or Linux mint, install it on a virtual machine like virtualbox or an unused PC laying about, and use it for a few weeks as your main computer. Learn to install packages, find your way around the terminal, and compile using gcc. You might even find you like it better than Windows or MacOS, if you're like me.
But, the reason I say to do that is because the raspberry pi is a stripped down, bare bones computer running a stripped down, bare bones installation of Debian with some odd configuration stuff thrown on top, so you may find it a bit challenging compared to a "normal" Linux distribution at first.
That said, Linux, the Raspberry Pi, and C/C++ are all wonderful, and you'll learn a lot about all aspects of computers and programming if you stick with it.
I think if you do that, most of your questions will be quickly answered. Maybe find some C tutorials on youtube that are aimed at compiling on Linux, and not just using some IDE (which, granted, you could also use instead. Code Blocks comes to mind).
Edit: Okay, I'll answer some of these questions directly.
"gcc" and "g++" are the gnu c compilers that will be installed, or at least available in the repositories of any Linux Distro.
Open a terminal and type "gcc -v"
If it outputs version info, gcc is installed.
Otherwise, install it with the command "sudo apt install gcc"
"sudo" is for super user do, and will prompt you for a password. Asterisks won't appear as you type - just type it and press enter.
"apt install" tells apt, your package manager, to install a package.
"gcc" is the GNU C Compiler package that you're installing.
To then compile a c file, let's say "hello.c", type:
gcc hello.c -out 'hello'
This will make a binary file called "hello" which you can run by typing "./hello"
You might also find programs like "cowsay", "htop", "nano", and "vim" to be fun or useful to mess around with while learning. Try typing them into the terminal and seeing what happens
