Go into a terminal and type adept_updater or look to see if you have
synaptic installed and use that
you could also from the command line...sudo apt-get update then sudo
apt-get upgrade...

It seems that you are logged in as non administrator. If it is so, then you
wont be able to install anything.
If you installed it yourself then user your login and password same as the
one to install it.

Non administrator are not allowed to change anything in linux.

Yes, I do have administrator privileges, the problem is I don't know
what command to give when I open terminal. I start with sudo adept and
get the response "adept command not found." When I do sudo apt-get, the
next response is my password. But then from there I am lost. What do I
do at that point to change the permissions?

this is the results of my sudo apt-get. To do anything like a
package install, you must type: sudo apt-get install (package name)
minus ( ) and hit enter, you will get a password prompt, enter your
password and hit enter, apt will do the rest.

stewart@stewart-desktop:~$ sudo apt-get
Password:
apt 0.6.46.4ubuntu10 for linux i386 compiled on Mar 14 2007 17:43:24
Usage: apt-get [options] command
apt-get [options] install|remove pkg1 [pkg2 ...]
apt-get [options] source pkg1 [pkg2 ...]

apt-get is a simple command line interface for downloading and
installing packages. The most frequently used commands are update
and install.

Commands:
update - Retrieve new lists of packages
upgrade - Perform an upgrade
install - Install new packages (pkg is libc6 not libc6.deb)
remove - Remove packages
source - Download source archives
build-dep - Configure build-dependencies for source packages
dist-upgrade - Distribution upgrade, see apt-get(8)
dselect-upgrade - Follow dselect selections
clean - Erase downloaded archive files
autoclean - Erase old downloaded archive files
check - Verify that there are no broken dependencies

Options:
-h This help text.
-q Loggable output - no progress indicator
-qq No output except for errors
-d Download only - do NOT install or unpack archives
-s No-act. Perform ordering simulation
-y Assume Yes to all queries and do not prompt
-f Attempt to continue if the integrity check fails
-m Attempt to continue if archives are unlocatable
-u Show a list of upgraded packages as well
-b Build the source package after fetching it
-V Show verbose version numbers
-c=? Read this configuration file
-o=? Set an arbitrary configuration option, eg -o dir::cache=/tmp
See the apt-get(8), sources.list(5) and apt.conf(5) manual
pages for more information and options.
This APT has Super Cow Powers.
stewart@stewart-desktop:~$

Here is a link that i have saved when i was a newbie
Its heading is how to install anything in Ubuntu.

http://cutlersoftware.com/ubuntuinstall/

Did you enable the other repositories in ubuntu Check all the repositories
(Universe, Multiverse, Restricted, official).

Try installing Flash plugin

sudo apt-get install -y flashplugin-nonfree

What does it say??