Installing stuff with Ubuntu is a very different experience. Ubuntu comes with stacks of applications ready to use, but there is likely to be other stuff you want to run
Read it at the lo-fi librarian
The Advanced Package Tool (APT) is the magic that lets you download, install and update. This is command driven, but there are a number of graphical front ends that make these tasks much easier. The one that I have been using most is Synaptic Package Manager, this is located in the Systems menu and is password protected.