I am working in the old gForth tutorial so I can add the graphics I need to my game, but I can't even run the demo.
How do I get libtool to run here?

libtool is a friend (or part??) of autotools (automake/autoconf), the GNU Unix build tools. gnu.org has the source and the manuals. It's typically standard available in a Linux package manager. For Windows, it may be part of some GNU build chain, like mingw (no idea really, I don't use Windows, but that's the first place I'd look).