How to solve "building the main Guest Additions module Failed"

You lack the make command. Make is a utility that is often used to build programs from source; it runs the compiler on every source file in the right order. You need to install the make package, and possibly others: the C compiler, and the kernel headers (files generated during the compilation of the Linux kernel, that are necessary to compile third-party modules).

I hardly ever use CentOS, but I think the right command is:

yum install gcc make kernel-devel

or (will install more than you need)

yum groupinstall "Development Tools"

You may need to install other packages as well.

You need to run this command as root; depending on whether you use su or sudo:

su -c 'yum install …'
sudo yum install …

On a current CentOS 7 minimal install you need:

sudo yum install gcc kernel-devel-$(uname -r)