Where is the package manager

[Tchize]

Hello,

I decided, out of curiosity, to try gnome instead of kde. i did an
apt-get install ubuntu-desktop. The gnome env was fast to load, but i
have a few concerns. I suppose they can be easily solved:

1) I can't find an equivalent of adept (ubuntu package manager) from kde
in gnome
2) I use a lot klipper in kde, it's a clipboard history. Is there any
gnome equivalent i can load?
3) where is the pdf reader? (i use kpdf in kde)
4) Is there a droppable console, like yakuake
5) How can i have my background change on a regular basis, like in kde? :D