account erased?

[ephoni]

hey there, i'm definitely (and apparently) not an experienced mac user. i should also say that i bought this computer (powerbook G4) used.
The Problem:
I seem to have erased/missplaced my main user account data. i have 2 accounts: Administrator and another called "Andal". i've always only ever logged in as Andal. The previous user set up both of these account, however, and only told me the Administrator password. I don't know the password for Andal, and went looking for it this morning. I logged into the Administrator account for the first time, and came upon documents belonging the Andal account that were locked. informations said, under "ownership & permission" that i had "No Access." I then changed "Owner" under "Details" to "Administrator" which then allowed me access.
When i proceeded to log back into the Andal account, I was blocked from opening any documents. All of my iTunes said something like, "can't be played because original song can't be found.."
So, i logged in again as Administrator to undo the "ownership & permission" change i'd made. The result was that i could no longer access any Andal information from either account. some messages said file was missing, i had "no permission" or item was "on a locked disc"
The only hope that i have for this data existing is that my hard drive information says that i am still using the same amount of data storage... Please, Please help me.
sincerely, Ephoni