Installing apps

Ok its been awhile since Ive used KDE 3.. how do we install apps? I installed MUON but it tried to download like KDE 4 it looked like it installed alot of KDE 4 resources. I have synaptic installed now.. Not profecient with it I am use to a graphical interface but learning. also how do we update the OS? I tried typing in ADEPT not found.. I looked though the menus in classic mode and I dont see an updater??? I installed TDE though a CD instead of a sudo apt-get method. ~ Christopher ~