[ubuntu] With only Ubuntu 19.10 installed: No sound, screen brightness control and wifi

Dear Everyone !

I had Windows installed on a 1 TB internal hard drive inside a
HP Pavilion laptop.

Everything was working fine.

I replaced the 1TB internal hard drive with a 2TB internal hard drive.

After installing only Ubuntu 19.10 on the 2TB internal hard drive (with
no Windows or Mac operating systems installed alongside Ubuntu 19.10).

I now have no sound control. Also, when I try to play an audio file VLC
media player says:
Audio output failed. The audio device default could not be used.
No such file or directory.

I only have Ethernet connection no wifi internet connection,

I also have no screen brightness control.

Very disappointing compared to the Windows installation.

All of these kind of hardware drivers issues makes it extremely hard
work for a member of "Joe Public !!" to install and use Linux.

I reckon it must put a lot of people of from persisting in doing so.

Thereby making many people more inclined to go back to using
Windows or Mac OSX where hardware drivers appear to install
themselves more by "Magic" !!

Can anyone please help me with these issues.

Thanks !!

Paul Clarke