I have a REALLY old iBook, and I can't download flash, or new versions of browsers. What do I do?

I have an Apple iBook from probably 2004. It was broken and unusable until a few days ago, and I tried to download Flash, the newer Safari, etc, but I can't. For example, I go the the Adobe website and Select Macintosh. It won't continue, just stays at that page no matter how much I click. It won't open pop up windows either. Without Flash, most of the internet won't work properly. PLEASE HELP ME. Are there certain settings I need to fix or what?