Noob OS question

I just acquired an old G3, with OS 9.2 on it. I want to upgrade the OS to the new one, but have a question prior to doing so.

Is a new OS a completely blank system - like, will I have Internet Explorer and the basics I need that are on the machine already? Or does the OS come with any basic necessities such as IE?
Is there a way to keep the software that's on there currently, for which I don't have the disks?

Thanks in advance!

How old is the G3, what's it's processor speed ?

Mac OSX is the present system and you'll get Mail(email program) safari (web browser-much better than IE) and lots of other basic stuff like a PDF viewer (preview) a text editor and some more. So it's not basic, you get a lot with it and you can always download other freeware apps from places like www.macupdate.com and www.versiontracker.com.

If you install the new version then it can be installed to leave your present software in place but their maybe a few problems if your computer isn't fast enough to run it or if your harddrive is over 8 gigs and not partitioned. Then you'd have to reformat your harddrive into partitions and would loose the data. How big is the harddrive ?