[NTLUG:Discuss] New to Linux and seeking assistance

[James Good]

Greetings and thank you for allowing me to join.

As a way of introduction, my name is James Good.  My amateur radio call 
sign is KD5VXH.  I live in the Northwest corner of Tarrant County, the 
Parker County/Tarrant County line is less than a mile from my house.

My problem:  The computer that I use had been running Windows 10, with 
all of its constant updates/upgrades.  Almost every day I would find at 
least one, sometimes more, updates/upgrades had been made to the 
operating system and somewhat related changes had been made to other 
parts of other programs on the computer.  Those changes would need to be 
corrected if I wanted those other programs to work.  Those 'other 
programs' were all amateur radio related and used for digital mode 
operations on both HF and VHF/UHF.  The updates/upgrades from Microsoft 
became so frequent and so frustrating that last week I located a disk 
that I had burned with an iso of Ubuntu 18.04.1.  Thursday was the day I 
made the change after testing Ubuntu without installing it.  All seemed 
to work just fine.  And it works better than it ever did with Windows 
(especially any version after Xp).  I got the install disk to install 
Ubuntu to the computer (of course, all of the Windows files, programs, 
and data that had been enjoyed are now history). Over the past two or 
three days, I have been trying to learn how this new (to me) operating 
system really works.  If the install disk asked or prompted for a 'user 
password' during the install process, I don't remember seeing it.  And 
now, any time I try to add anything new using the Terminal application, 
I am asked for my password.  As stated, I don't remember seeing a prompt 
to enter a password during the install process.  Now, not knowing what 
that password might be (if one was set) it appears that there is very 
little I would be able to actually do other than a complete re-install.

Is there any way to view the passwords that might be on the computer?  
And how could I change any password already set if I can't get into the 
'root' directory to make the change?

Thank you in advance,

James Good KD5VXH