Hi, Anuj! Welcome around.
I recommend against using random blogs or tutorials as guidance on how to install the software, especially that the software’s own documentation provide more direct steps on how to install it. If you check the Download page on the documentation part of the website, you will find clear steps of all the different ways to install (download) Caddy. The link I included takes you directly to the steps of installing Caddy on Ubuntu. That should get you started.