Upgrading from really old version

I need to upgrade WordPress. Problem is, I don’t know if I can. I don’t even know what version I have. (I didn’t install it, I have never used WordPress before.) In the admin footer it says that I have version 1.0.2 but in the actual forum the footer says 1.197. Either way it is old. I found something that says if you are running 1.2 you have to upgrade to 1.5 to upgrade to 2.0. But I can’t find an upgrade from 1.0 to 1.2. Do I even need to make that upgrade? If I can just upgrade to 1.5, does anybody know where I can download it? I can’t find that either. OR would it just me much easier and time efficient to scrap the whole thing and start over. I need help. ??