If your computer runs Windows, then you install the Windows version, if your computer runs on Linux you install the Linux version.
Both operating systems support 32 or 64 bit processors. You need to find out if your computer is 32 or 64 bit system. The vast majority of modern computers use 64 bit. But 64 bit computers can run 32 bit software too.
If you install the 64 bit version and it doesn’t run, try install the 32 bit version. When you do the trial installation, do have any other software running! in case it causes a crash.