I'm stuck with a limited account and no disc

Hello. I'm at home and I'm stuck with a limited account.

What I would like to know is how I can access an admin account, or even just set a couple more hours of time to my account (or is that not the easier option?), if I don't have an admin password or the disc thing to reset stuff on the computer. I also think that super admin account, or whatever it is, is on the main login page with a password I don't know.

Can you please help me?