NOOO YOU'RE NOT STUPID AT ALL </3 Linux is a little weird with ren'py and I did a little digging and it said that "unpack the tarball, change into the renpy-<version> directory, and then run renpy.sh" !! I can't exactly do much after that but I hope this works, and I think the ren'py website might have better advice for you! I do hope you enjoy :D