- Dakota and 2) Helvetica Neue Light
This question is not related to LibreOffice. Fonts are managed by the operating system (which you did not mention). If you need additional fonts, you need 'em to download from a free font service on the net and install it using the method provided by your operating system. LibreOffice does not provide additional fonts.
Dakota Schriftart - 1001 Free Fonts (attention free only for personal use, otherwise you need a commercial license)
Free Helvetica Neue Light Font Download - you need to check the license yourself.
LibreOffice does not provide additional fonts.
Just splitting hairs: LibreOffice Portable for Windows does actually provide OpenSymbol 
But this is a very particular case, of course.
Thanks for the clarification - additional means: additional to those provided during installation. And next time I’ll replace LibreOffice by The Document Foundation to make clear, that I’m not talking installation package, which of course installs a bunch of fonts (but I’m pretty sure getting “Who’s that” response from OPs).
As far as I perceive the guy’s request seems legit as these fonts are not present. Let’s get this karma up to 5 at the same time.
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