Hello and welcome.
Now there's a blast from the past! Let's see if we can get you back up and running. I'll have to put on my thinking cap to remember OS 9.2.
-Is it 9.2/9.2.1/9.2.2?
-Which model G3?
I believe if you keep holding the Shift key down until you see the Mac OS 9.2 splash screen during startup, it will say Extensions Off and not load the extensions, which should get you in the Finder. You can then disable/turn of file sharing, and see if you can then restart and use the G3.
Let me know, as I actually currently have an old Power Mac 8600 running 9.1 setup right now, so I should be able to help you out.
C