In Ubuntu/Linux Mint you can install softwares from Software Centers or via PPA/Synaptic . If any software is not available in deb/software center/ppa and it’s only available in rpm, than you can convert that rpm file to deb package with one command using terminal.
This is a widget panel. To remove this text, login to your WordPress admin panel and go to Appearance >> Widgets, and drag & drop a widget into this widget panel. If you want to leave this area blank, simply put a blank Text widget into this widget panel which will overwrite this text.