Welcome! Linux is a kernel, the operating system is GNU/Linux.
To see what video card you have, run in a terminal
lspci|grep VGA
(GNU/Linux is case-sensitive, i.e. VGA is not vga)
Things worth trying to fix
* the brightness control, you could try adding a acpi_backlight=vendor
parameter to the kernel in GRUB.
Put it on this line GRUB_CMDLINE_LINUX_DEFAULT=
sudo nano /etc/default/grub
Ctrl+X and Enter, Enter to exit
sudo update-grub
Then boot and see if that made a difference.
* the resolution, you could try moving xorg.conf to another name and if
that's not enough, upgrading the Linux-libre kernel and the X server.
sudo mv /etc/X11/xorg.conf /etc/X11/xorg.conf.backup
Boot to see if that did the trick. If not, you can try a new kernel from
http://jxself.org/linux-libre/ and installing the -lts-sausy xserver packages
using the Synaptic package manager. Once again boot to see if this helped.
Why things like this don't work always (I had no problems with my widescreen
resolution nor brightness) automatically is because there is so much
differing hardware. Things were much more standardized when we used desktops
but laptops are a nightmare and phones and tablets are probably even worse...
