You should never use GLUT. It hasn't been updated since 2001. FreeGLUT on the other hand is just fine. So use FreeGLUT instead of GLUT if you can.
If you want to learn OpenGL, I recommend either buying the book cocoaplus mentioned (OpenGL SuperBible by Richard S. Wright), or use this fantastic website: https://learnopengl.com/
Do not limit yourself to just lessons with GLUT/FreeGLUT. GLUT, FreeGLUT, and GLFW, are all just OpenGL toolkit libraries. They allow the user to create and manage windows containing OpenGL contexts on different platforms and also read the mouse, keyboard and joystick functions. These libraries do not draw anything to the screen so it does not matter which one you use.