Need some help on Apple iBook Clamshell

Hi all. Well firstly, I never owned an iBook and know nothing about it. But heres my question and hopefully someone can help. The version is 10.3.6 mac os x 366 mhz power pc G3. 128 mb. It was purchased at a second hand store and protected by a admin password so no changes can be made to it or updates and you can only log on as a "teacher" and you are extremely limited to anything you can do to the computer as far as updates go and I have found that there are quite a few waiting to be installed, but again I cant update without admin pass. I found a password reboot disc on ebay for ten dollars that I would buy to reset the password for it, however I would need to know first if I can play a game called runescape on it. I am not sure if the system would be compatible with the game or not, or even if java is available on this for any games. At the moment I cant watch videos because it keeps telling me flash is out of date and I am assuming because the pc hasnt been updated in so long but not sure. I have tried to load the game and I get nothing but a black screen and a pop up that says to install java but then it says java isnt available for my system. (from not updating?) I just hate to waste money on it to find out that I cant play that game on it or even watch videos on you tube. Any input is greatly appreciated. Thank you.

Ok..

Since no one replied..I am going to update this thread for anyone in the same situation as myself as to what I am going to do to solve this problem. I ordered the panther os reinstall kit so I can just reinstall the whole operating system and do the updates and reset the system pass etc..I originally had no intention of doing this or spending money but this funky blue thing has grown on me and I refuse to let it defeat me! I have found that runescape does indeed now have a mac download client you can add to your desktop and you can reboot the game itself from there..as for the terrible RAM..I have ordered a 512mb ram stick for it (its the short one..it will not accept a full length stick)..so that will give it some more ram. I have found out that you cannot install or upgrade a video card as it is basically built into the motherboard..so not much you can do there. Hopefully after receiving my discs and reinstalling everything and updating the java on it..we can play runescape. I will let you know how that turns out!!

Thanks for the update. You do know that's a 10-year-old (or possibly older!) computer, so yeah it's going to be quite limited for some (a lot of) things.