Professional VHDL simulators are more expensive than most individuals can afford. But fortunately, there are many free and legal alternatives that you can download and install.
Microsoft Windows is the easiest to install on, but many simulators also have a Linux version. FPGA vendors usually only support the Red Hat Linux distribution. But with a little effort, you can make it work in other distros, including Ubuntu.
Mac OS is the most challenging platform because there’s only one open-source simulator that works natively.