I only use Terminal when I have been given exact instructions on what to type in. So, I am a novice. But, I was trying to create a bootable USB drive of Ubuntu, which requires Terminal commands (that I got on another site). But, when I run a SUDO line command, I am told I don't have permission to do that. Even though I am the only user and the only admin of this Mac. Por que?
The only reason you should get that message because your account is not in the "administrator" group. Go to the control panel and choose "Accounts" and verify that the word "Admin" is under your name. If it isn't, verify that there is not a separate administrator account other than the one you are using.
The other possibility - maybe you're running some version of sudo other than the one installed in /usr/bin?