You can request that packages be added. There is a section of this forum for that purpose. You could also build it yourself. As a new linux user it would be a worthwhile challenge in my opinion. Or you could enable one of the slackware repositories in gslapt and audacity may be there. Lastly, you could you could try linuxpackages.net and search for it there. These are listed in the order of preference and probably safety. If you do download a slackware package (.tgz) then you will need to install the package as root with the following command: installpkg packagename.tgz.