What does this mean? I am trying to upgrade my version 12.04 Ubuntu

Question

The following packages were automatically installed and are no longer required:
  mingw-w64 sbsigntool libnet-ssleay-perl gir1.2-timezonemap-1.0 linux-image-3.5.0-22-generic realpath efibootmgr libunistring0 diffstat
  libdmraid1.0.0.rc16 libdebconfclient0 binutils-mingw-w64-i686 libxml-parser-perl liburi-perl libhtml-parser-perl kpartx-boot libopts25
  gir1.2-json-1.0 libhttp-daemon-perl linux-headers-3.5.0-22-generic autogen libfont-afm-perl libhttp-negotiate-perl libfile-listing-perl
  libhtml-form-perl gcc-mingw-w64 user-setup gcc-mingw-w64-i686 kpartx libhtml-tree-perl libencode-locale-perl rdate libhttp-date-perl
  libmailtools-perl liblwp-protocol-https-perl libhttp-cookies-perl libhttp-message-perl binutils-mingw-w64-x86-64 libdebian-installer4
  libopts25-dev libnet-http-perl btrfs-tools apt-clone localechooser-data linux-headers-3.5.0-22 gcc-mingw-w64-base libhtml-format-perl
  libgettextpo0 libsocket6-perl gcc-mingw-w64-x86-64 libhtml-tagset-perl archdetect-deb dmraid python-pyicu libkms1 libwww-perl mingw-w64-dev
  libio-socket-ssl-perl libwww-robotrules-perl liblwp-mediatypes-perl gir1.2-xkl-1.0 libio-socket-inet6-perl
Use 'apt-get autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
dianne@dianne-Inspiron-3437:~$ sudo do-release-upgrade
Checking for a new Ubuntu release
No new release found

Answer 1

The Output of your message meaning:
You have unused packages that had at one time been installed to support some other application(s) that are no longer installed. The packages can be removed. It's also showing you the command to remove the leftover packages: sudo apt-get autoremove.

You can upgrade from Ubuntu 12.04. I was already sure, but just before posting, I tested to verify that it would work. I installed 12.04 LTS on a VM and upgraded it without any problems.

You'll have to run a combination of these commands:

$ sudo apt-get update
$ sudo apt-get upgrade
$ sudo apt-get dist-upgrade

After the upgrade commands, run this:

$ ls /var/run/*reboot*

If one of these lines included in the output, reboot the computer to make changes become in effect:

/var/run/reboot-required
/var/run/reboot-required.pkgs

Between the commands, look at the screen as you already have and perform the steps provided by the screen's output to fix problems. In the case of your current problem on your screen, it's telling you to perform this command:

$ sudo apt-get autoremove

The error No new release found can be resolved with the third command in the list above. The dist-upgrade is different from the upgrade option, whereas the dist-upgrade will remove outdated libraries and remove applications that were installed with the old libraries.

If they are applications that you need, you can address those issues and reinstall the ppa's or other dependents later, or get updated versions of those programs that don't carry over.