You need to resolve this issue:
/usr/local/lib/ruby/gems/3.0.0/gems/jekyll-4.2.0/lib/jekyll/commands/serve/servlet.rb:3:in `require': cannot load such file -- webrick (LoadError)
When you have an error, search StackOverflow/Google for a solution. This error was encountered in the Jekyll forums.
You can try installing Ruby 2.7 - as 3.0 is still new. Or reinstall global gems. You can try these solutions
Later on the thread
One solution for mac:
bundle add webrick
I’m using Mac and never had to directly install webrick
in a project or globally.
You might need to make sure you’ve set up your PATH correctly, so that Ruby and gems can be found properly. Maybe webrick is installed globally but just can’t be found.