Installing fonts in any Linux based OS is very very easy:
1. Copy the extracted (.ttf or .otf) font files into fonts:///
2. Copy the font files (.ttf or .otf) to fonts:// in the File manager
OR
2. Go into the /home folder, in the menu select View > Show Hidden Files, you will see the hidden folder .fonts (if not, create it) then copy the font files there.