Photon713

Received installation of Linux Mint and began the setup process and a temporary password was assigned for my Linux install..."1234". The password worked for a day or two and I continued to install the leftovers of Linux load. My password was change to a 6 letter value...value unknown and cannot work any further on my Linux install. How can I get a new password to be assigned by a superuser? I suspect it was changed to a different password by the Boot process or I had inadvertantly hit a couple of keys unbeknown? I had done a boot during the build process. I have been a Linux Mint wannabe for 2 days. I need a superuser to create a temporary p/w to be changed promptly.