Ubuntu – Cannot access the file: Permission denied – Virtualbox

I have downloaded Virtualbox in order to run Android in it I have set up everything and tried to start it but unfortunately 2 errors have came up.

1. Failed to open a session for the virtual machine Android.
   The virtual machine 'Android' has terminated unexpectedly during startup with exit code 1

   Details:

   Result Code: 
   NS_ERROR_FAILURE (0x80004005)
   Component: 
   Machine
   Interface: 
   IMachine {480cf695-2d8d-4256-9c7c-cce4184fa048}
   

2. Kernel driver not installed (rc=-1908)

   The VirtualBox Linux kernel driver (vboxdrv) is either not loaded or there is a permission problem with /dev/vboxdrv. Please reinstall the kernel module by executing

   /etc/init.d/vboxdrv setup
   

   as root. If it is available in your distribution, you should install the DKMS package first. This package keeps track of Linux kernel changes and recompiles the vboxdrv kernel module if necessary.

   So it typed in the /etc/init.d/vboxdrv setup into the terminal and that's what came up:

   /etc/init.d/vboxdrv setup
   Stopping VirtualBox kernel modules ...done.
   Recompiling VirtualBox kernel modules
   /etc/init.d/vboxdrv: 334: 
   /etc/init.d/vboxdrv: cannot create /var/log/vbox-install.log: Permission denied
    ...failed!
     (Look at /var/log/vbox-install.log to find out what went wrong)
   

   After that as it was saying in the terminal I typed in /var/log/vbox-install.log to check out what went wrong.

   /var/log/vbox-install.log
   bash: /var/log/vbox-install.log: Permission denied
   

   As the permission is denied I have typed in 'su sudo' to be as root:

   su sudo /var/log/vbox-install.log
   No passwd entry for user 'sudo'
   

   So I tried:

   su /var/log/vbox-install.log
   No passwd entry for user '/var/log/vbox-install.log'
   

   And then:

   sudo /var/log/vbox-install.log
   [sudo] password for mroovka: 
   sudo: /var/log/vbox-install.log: command not found
   

   So I just typed in 'su' then tried to check the /var/log/vbox-install.log again but the outcome was…

   mroovka@mroovka-N102SP-N100SP-N101SP:~$ su
   Password: 
   root@mroovka-N102SP-N100SP-N101SP:/home/mroovka# /var/log/vbox-install.log
   bash: /var/log/vbox-install.log: Permission denied
   

So I don't really know what to do, as I have only one account and I am the administrator.

Thank you in advance for your help.

PS. I know this question may be duplicate but I read a lot about it and it is very challenging for me to solve this issue.