Jekyll: Cannot install jekyll on MacOS

The Output I Wanted

Establish a GitHub Pages website using jekyll.

• [x ] I updated to the latest Jekyll (or) if on GitHub Pages to the latest github-pages
• [ x] I read the CONTRIBUTION file at https://jekyllrb.com/docs/contributing/
• [x ] I am on macOS 10+
• [x ] I was trying to install.

My Reproduction Steps

My approach is _trial and error._ Originally, I received the following error several times: __(Gem::FilePermissionError)__ For example,

ERROR: While executing gem ... (Gem::FilePermissionError)
You don't have write permissions for the /Library/Ruby/Gems/2.3.0 directory.

Next, I tried several different approaches, including _rubyonrails_, without success. Now, I am using Xcode version 9.3, ruby 2.5.1, and gem 2.7.6.
This approach looks promising. Now, my error is: __(Errno::EACCES)__ . This error appears to be associated with _rubyonrails_. I searched the web and found people had difficulty removing _rubyonrails_.

_Note that t successfully performed several installations where above I did not._

Fetching: public_suffix-3.0.2.gem (100%)
Successfully installed public_suffix-3.0.2
Fetching: addressable-2.5.2.gem (100%)
Successfully installed addressable-2.5.2
Fetching: colorator-1.1.0.gem (100%)
Successfully installed colorator-1.1.0
Fetching: http_parser.rb-0.6.0.gem (100%)
Building native extensions. This could take a while...
ERROR: While executing gem ... (Errno::EACCES)
Permission denied @ dir_s_mkdir - /usr/local/lib/ruby/gems/2.5.0/extensions/x86_64-darwin-17

Building native extensions. This could take a while...
ERROR: While executing gem ... (Errno::EACCES)
Permission denied @ dir_s_mkdir - /usr/local/lib/ruby/gems/2.5.0/extensions/x86_64-darwin-17

__It appears that I close to a solution:__ Remove _rubyonrails_.

I would appreciate help.
Thanks
Paul