It should pick up the TTF/OTF fonts on your system, which you can download in HaikuDepot. Let me just check on a new install …
Right, a brand-new install of B4 has Noto and WenQuan Yi (which is only relevant to Chinese script AFAIK). Haiku itself comes with Bitstream Charter but that is in PS format, which LibreOffice seems to ignore.
So fire up HaikuDepot and search for “font”
If you have old favourites that are not listed there, just drop the .TTF files in /boot/home/config/non-packaged/data/fonts/ttfonts/ (create the directory if it doesn’t exist). No need to reboot but it will help if you restart any font-aware programs.