Used iPhone with restriction passcode lock

Hello,
I recently replaced my water damaged 1rst gen iPhone, with a used one.(I'm not sure if it's 2nd gen or 3rd.) Shortly after I got the phone, I went to go to the app store to download a few and realized, i had neither the itunes icon, nor the one for the app store! Ive read about and tryed resetting my homepage, but it didn't work. I then attempted to reset all settings but apparently, there is a lock on it. I've tryed contacting the previous owner, to no avail. What can I do? Also, was wondering: if my old iPhone apps are retreivable somehow, as the computer I had took a dive & I hadn't sunk it but once anyways? Thank you.