Download the Ubuntu Desktop ISO
rather than adding a GUI to the Server version, you can do all the same tasks it’s just better than adding your own desktop environment and you can stop start the GUI service like a windows service,
Be aware though unless you have a CGI or Web App like Webmin installed Your only way to access the OS will be via SSHD and BASH Commands.

Ubuntu Desktop 26.04 LTS

Download Ubuntu Desktop

However, if you want a headless OS

Ubuntu Server 26.04

Download Ubuntu Server

Bitvise SSH Client for Windows

Download Bitvise SSH Client

Bitvise SSH Server is used to accept connections from SSH clients for BASH and SFTP

Text editor with BASH command line

You can use Vi or Nano I prefer Nano personally

To open a file and edit it for example if we wanted to edit the nginx webserver config
sudo nano /etc/nginx/nginx.config

Ubuntu Bash Command Cheat Sheets:

Ubuntu CLI Cheat Sheet (PDF)
Ubuntu Server CLI Cheat Sheet (HTML)

Create a bootable USB stick

Download Balena Etcher Bootable ISO Maker
Download Rufus Bootable ISO Creator

To install Ubuntu Desktop, write your downloaded ISO to a USB stick to create the installation media. This is not the same as copying the ISO and requires some special software.
both Rufus and Balena work with windows