Download Ubuntu 18.04:
Then, assuming you are currently running Windows, go to this page and follow the instructions to create a bootable USB stick. Reboot your computer with the newly created USB stick, and install Ubuntu. If you want to keep using Windows next to Ubuntu the most easy way is to have a dual-boot system, i.e., during startup you can choose to boot either Ubuntu or Windows. this tutorial will show you how to create a dual-boot. Of course you can also bring your notebook to the ICT servicedesk and ask them to install Ubuntu (but mention that you need version 18.04). Note that one could also use a virtual machine to install ubuntu, but students have experienced some issues with it over the past few years so we generally don't recommend it.
Nothing happens when I reboot with the USB drive
When rebooting your computer with the USB stick it may be the case that booting from your hard drive or SSD is preferred over booting from the USB drive, and the Ubuntu installation doesn't start. In that case, try rebooting again, and now try to enter the BIOS or watch out for a Boot order menu. Often, you have to press keys during start-up such as F12 or DEL. Once you found the boot order menu, make sure the USB drive has priority over your normal drive, and restart.
I cannot shrink my Windows-partition
In the case you manually create partitions during the process of installing Ubuntu 18.04.5, you might face an unshrinkable Windows partition. This usually happens when some unimportant files exist at the end of the Windows partition, use this manual to change settings. After shrinking, the settings can be set to their original values. In most of the cases this will remove the files at the end of the partition. In the case that you are still facing an unshrinkable Windows partition have a look at the defrag-events, but be careful not to remove any vital files when "just removing files".
The Ubuntu Terminal
Most of your interaction with Ubuntu will be done through the terminal, the number-one way of interacting with Ubuntu using your keyboard. A terminal can be started by pressing ctrl-alt-t.
Although the terminal commands may seem somewhat puzzling at first, you'll soon find out that the terminal is a nifty tool and allows for faster and more powerful access to all of Ubuntu's possibilities than the graphical interface and mouse. If you don't know your way around the terminal, have a look at this page.
Ubuntu is already pretty great out-of-the-box, but some customizations will make your Ubuntu experience even better.