Can't import Rails in Terminal, gives error message

Terminal - Rails import - Error Message

Last login: Wed Mar 26 20:45:26 on ttys000
Brandon-Courtneys-MacBook-Pro:~ brandoncourtney$ 
Brandon-Courtneys-MacBook-Pro:~ brandoncourtney$ ls
Desktop			Library			Sites
Documents		Movies			ganttproject.log
Downloads		Music			intro_rails
Dropbox			Pictures		java0.log
Google Drive		Public			temp
Brandon-Courtneys-MacBook-Pro:~ brandoncourtney$ cd intro_rails
Brandon-Courtneys-MacBook-Pro:intro_rails brandoncourtney$ rails new myproject
Rails is not currently installed on this system. To get the latest version, simply type:

    $ sudo gem install rails

Brandon-Courtneys-MacBook-Pro:intro_rails brandoncourtney$ $ sudo gem install rails
-bash: $: command not found
Brandon-Courtneys-MacBook-Pro:intro_rails brandoncourtney$ sudo gem install rails
Password:
Sorry, try again.
Password:
Building native extensions.  This could take a while...
ERROR:  Error installing rails:
	ERROR: Failed to build gem native extension.

    /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby extconf.rb
mkmf.rb can't find header files for ruby at /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/include/ruby.h


Gem files will remain installed in /Library/Ruby/Gems/2.0.0/gems/atomic-1.1.16 for inspection.
Results logged to /Library/Ruby/Gems/2.0.0/gems/atomic-1.1.16/ext/gem_make.out
Brandon-Courtneys-MacBook-Pro:intro_rails brandoncourtney$