Q:

Is it practically useful to decline GUI for a newbie in Ubuntu?

My Ubuntu is 12.04.
I have just started learning Linux (Ubuntu in particular).
To remember terminal commands quicker, I'd like to not use a GUI.
However, I can't launch installed programs because I don't know where they are.
For example, I have a PDF file. I know that there is a program to view such files.  If I was using a GUI I would just click on the PDF file and it would open in Document Viewer 3.4.0.
Then I would like to launch Firefox Web Browser. Even if I know it is installed, how to find the file to be launched using just CLI is a mystery to me.
Could you suggest anything?

A:

Honestly, for most of these programs it is enough to simply know their name. When installed from a repo, they tend to add themselves into your path, or a symbolic link to the applications binary is added into a folder in your path already.
Also, man (manuals!) is your best friend!
man apt-get | less

Then you can scroll up and down, line by line rather than having to go by entire pages, (depending on your version/distro, this may be the default functionality of man) it can be very useful when trying to get that next line of output.
And last, but definitely not least, if you are new to linux, your package manager apt-get, is going to be your best friend. For experience you should install some programs from source, but knowing your package manager and being able to search it will be invaluable as a time saver.
Hopefully this helps some.

