The idea of leaving the operating system you are comfortable with can be very daunting and I don't recommend doing so at first. Instead, I suggest users of proprietary software first begin replacing their software one at a time with a free alternative.
| Proprietary | Free Software | 
|---|---|
| Microsoft Windows, Apple MacOS | Trisquel, Parabola, Debian, Ubuntu | 
| Microsoft Office | LibreOffice | 
| Google Chrome/Microsoft Edge | FireFox | 
| Adobe Photoshop | GIMP |