This looks like somehow you accidentally did an OEM installation of Ubuntu and then used the OEM user account as a normal user account. If you saved important data on this system, DO NOT go through the setup wizard you're seeing at bootup, as this will probably wipe all your data. The best solution at this point is to boot from a live ISO of Ubuntu, back up all your data to an external drive, and then install Ubuntu from scratch (using the "Install Ubuntu" option at bootup, not the "OEM install (for manufacturers)" option). You will need at least two external drives to do this - one to flash the live ISO to and boot from, and the other to store your data. Do not attempt to use the same flash drive to boot from and to store your data, as doing this could result in your data being lost when you shut the computer down.
If you're wondering why on earth this weird setup option exists, here's why.
The OEM installation option is designed to allow computer manufacturers to ship systems with Ubuntu preinstalled. Basically, if you are selling computers with Ubuntu, you can set them up using the OEM installation option, log into the OEM user, install any additional software and drivers you want to ship with the system, then run the "Prepare for shipping to end user" shortcut and shutdown the computer. At that point you would package the computer up and sell it. It would never be turned on by you again after running that shortcut.
When the end user gets the system, they boot it and then get the setup screen you're looking at. This allows them to set up the system for themselves.
This works out great if you're selling a computer, but not so great if you're installing it for your own use. From my research, I believe the OEM user is supposed to be deleted automatically during the setup procedure, and if that user has any important data in it, it will probably be lost.
