What are you trying to install? All programs can be found in synaptic. Very
rarely you need to build from source.
http://psychocats.net/ubuntu/installingsoftware

New operating system = new way of installing applications (and just about
everything else)

Windows way: buy a programme or hunt on the internet for it. Each programme
has its own installer. Viruses proliferate on programmes you download on the
internet. The programme installs where you tell it to install and it may put
an icon on the desktop and start its own group in your menu which you have
to clean up every once in awhile.

Linux way: the application is free and found in a menu of a package manager
on maintained repositories that are free of viruses. The installer is
standard. The application does not allow you to install it where you want
and it never creates a desktop icon and messes up your menus. It creates an
icon in pre-established groups that never change.

In Windows follow Windows protocols and in Linux follow Linux protocols. If
you confuse the two you will never adapt.

Are you using Snaptic or software center? I haven't had any problems with
Snaptic
Manager myself.

Many things seem frustrating until you see how they work.

When you say "find a package" are you talking about searching in
synaptic or the software center to find a package in the repositories?
Or did you already download a deb package and you just want to install it?

You can install an existing deb package file either from the file
manager or the command line.

On the command line, type "sudo dpkg -i <name of package file>" to
install it.

Or, if you prefer to use the file manager, just right click on the deb
file you downloaded and you will see an option to install it.

BTW - the firefox that comes with ubuntu has a package manager plugin.
If you are downloading a deb file the firefox plugin will offer to
install the package for you.

I wasn't thinking of a particular program just past headaches doing so with
various attempted downloads and install under Linux. Happened several times.