Hi. There's not Times New Roman choice in my fonts list of LibreOffice. But if I type it in the field, it accepts the choice. So, I suppose it's installed. How could I add it to the list? And, moreover, how to make it the default choice? Thanks.

To install the actual TimesNewRoman font (so that you're not being shown a nearest-match substitute):
sudo apt-get install ttf-mscorefonts-installer

As for"how to make it the default choice?", idunno what controls specific to LibreOffice are available.
Check the helpdocs ~~ maybe a default setting is specified for a (each) document template.
For changing default across all GTK desktop apps, you can run lxappearance ( aka 'controlCenter -} Desktop -} Change Gtk2 and icon Themes )

Just google"set default font for LibreOffice Writer" and all will become clear.

skidoo wrote:sudo apt-get install ttf-mscorefonts-installer

and the actual TimesNewRoman font is in the list. Then:

Tools => Options... => LibreOffice Writer => Basic Fonts (Western)

and set it as default. Many thanks to both of you.