My system is booting from the USB drive the problem is that after booting it shows the menu to select an option. And on selecting any option it leads to a blank screen.
I am trying to boot Ubuntu 18.04 from a USB live stick. I waited for about half an hour too after selecting install Ubuntu option, but it's not working. I have Dell Vostro 3568 8GB RAM, i5 7gen with AMD Radeon. I have made the live USB from startup disk creator which is preinstalled in Ubuntu.
So after much googling, I got the solution. It was very simple to fix that issue. It is about nomodeset.
When the USB/CD boots press E on grub menu it will lead to edit the grub.
Find the line which ends with quiet splash and add nomodeset in front of it. So it becomes nomodeset quiet splash. Whatever is there in front of it leave it as it is just add nomodeset in front of quiet splash.
Now press Ctrl+X to boot it normally. It will lead you to Try Ubuntu Without installing option. Now from here too you can install Ubuntu. As install Ubuntu option is always there in the live session. Now after installing Ubuntu we need to change nomodeset thing permanently so that we don't have to do it again.
After successfully installing the system will reboot. Press shift button for 5 seconds to get the grub menu after the system starts. If it does not work then try the same with Esc. The most important thing is that it is all about timing.
Now again repeat step 2 so that we can login in the system.
Now open a terminal and type sudo nano /etc/default/grub it will be having contents similar to this.
GRUB_DEFAULT=0
GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""
Find the line having quiet splash and add nomodeset in front of it.
Now save it with Ctrl+O and exit it with Ctrl+X. In order to update grub menu enter:
sudo update-grub
Update and Edit 1
After the above, I was able to boot and install Ubuntu 18.04. I was not able to control screen brightness after installing and setting grub setting as nomodeset so after searching on StackOverflow further I came across this question and I also got to know that nomodeset is a temporary fix. I updated my kernel and after this, I changed grub setting as it was earlier, i. e. removing nomodeset in /etc/default/grub and updated grub. Now it's working awesome.
Try Display brightness cannot be adjusted 18.04 if you face issues such as unable to control screen brightness.
