Do you have a Voodoo video card? If not, then that is why Lewpy's fine plugin won't work for you. Lewpy's plugin is a Glide plugin and is ment for use w/Voodoo cards only. What you want is Pete's plugins for the other types of video cards, just follow the links that Xeven provided and you should be up and running in no time.
Well, sorry friend, but even if you're playing with your brother in your home, you will break the law if you run the ISO and the CD at the same time (copyright rules, i'm afraid). But, I'm not your father, so to make a iso you simply have to get on the net a cd dumping utility: CDRwin, Isobuster, BlindRead are the most used (although even Adripsx will dump the CD for you), so serch on the net and get one of those.