Hi hlevy99!
The Core has no "apt-get" to handle packages. Instead of it, you will use the Apps application or the commandline tce-load (and others tce-* tools). Read the Wiki for more instructions of how Core works and to use the tools.
Do you have ethernet cable on your netbook? You can connect it thru ethernet then start apps and search for the firmware of your wireless interface. Firmware-b43 that you mentioned refers to a broadcom card I think... Have you found your wireless card in the wiki?