I have to download the game on steam or can I get it from the internet?

Steam

Thanks for information @Craigelbagel001

Like what Craigelbagel001 said, you can get it on Steam, you can also get it through GOG if that game is still on there site, or through the physical disc release of the PC version. The disc version needs the disc in the PC to play the game, Steam and GOG obviously does'int do that and I recommend those two instead if you can.