I'm using a chromebook, which doesn't have a whole lot of memory (for reference, it is a Acer Chromebook 11) and I've used Crouton to download Linux, in the form of Ubuntu 12.04, to start learning how to use Bash and Ubuntu. I have also downloaded other packages, like git, a special version of vim found on github, various python packages, and such.
I'd like to know how to get information like how much memory is being used on my computer and what packages are taking up the most space. I've looked around a bit on this site and couldn't find any answers. Any help would be appreciated. Thanks!