I suggest, you have good background in Digital Design. If not, start with any edition of "Digital Design" book or, alternatively "Contemporary logic design".
Download GHDL (VHDL compiler/simulator using GCC technology) or a little more friendly software tool boot.
Learn how to build a VHDL program with GHDL. Try to compile simple
"Hello, world!".
- Learn VHDL syntax with the open-source book Free Range VHDL. It is very important step.
