lualatex / babel / fontspec: **Package babel Warning: The following fonts are not babel standard families** and other warnings

Question

Aim and Problem

• I want to generate an English document that contains some single (simplified) Chinese characters.
• I also want to use the famous Noto fonts (from Google), see https://www.google.com/get/noto/ and https://www.google.com/get/noto/help/cjk/.
• Problem 1: With my simple document below I get the following warnings which I want to get rid off and ideally understand.

Warning 1

User Ulrike Fischer proposed \babelfont{tt}{Latin Modern Mono} for this warning.

Package babel Warning: The following fonts are not babel standard families:
(babel) * \ttfamily / lmtt
(babel) [lmmono10-regular]:
(babel) There is nothing intrinsically wrong with it, but
(babel) 'babel' will no set Script and Language. Consider
(babel) defining a new family with \babelfont.
(babel) Reported on input line 2.

Warning 2

Package fontspec Warning: Font "NotoSans" does not contain requested Script
(fontspec) "Simplified".

Warning 3

Package fontspec Warning: Language 'Chinese Simplified' not available for font
(fontspec) 'NotoSans' with script 'CustomDefault'.

(Potentially) Needed Steps to Reproduce the Problem

• I use TeXlive (up-to-date) on Windows and compile with LuaLaTeX..
• I downloaded the notocjksc fonts from https://www.ctan.org/pkg/notocjksc and put them in C:\texlive\2019\texmf-dist\fonts\opentype\google.
• I also downloaded noto fonts from https://www.ctan.org/pkg/noto and put them in the same path as notocjksc, see screenshot.
• Problem 2: It works but, I do not know which places (aka folders / paths) I can put fonts and if the folder name is relevant at all?! Can I also put it in C:\texlive\texmf-local\fonts for example? (Is there a logic or manual that I have to follow?).
• I opened the TeXlive Shell and generated the Font-Maps, see screenshot.

Problem 3: I do not understand why \babelfont[chinese-simplified]{rm}{Noto Serif CJK SC} works. When I open for example NotoSerifCJKsc-Black.otf then there is no Noto Serif CJK SC -- it is a Noto Serif CJK SC Black instead.

---

\documentclass{article}

% babel-package with option *english* as the document's default language
\usepackage[english]{babel}

% babelprovide for *english* (default language of the document)
\babelprovide[
    main,
    import,
    language = Default]
    {english}

% babelprovide for *chinese-simplified* (for some single words throughout the document)
\babelprovide[
    import,
    language = Chinese Simplified]
    {chinese-simplified}

%% Choose actual fonts for different font variants.
% Font for font variant "rm" (Serif)
\babelfont{rm}{Noto Serif}
% Font for font variant "sf" (Sans Serif --> Without Serif)
\babelfont{sf}{Noto Sans}
% Font for font variant "chinese-simplified"
\babelfont[chinese-simplified]{rm}{Noto Serif CJK SC}

\begin{document}

\begin{itemize}
\item English.
\item \foreignlanguage{chinese-simplified}{汉语。} (Chinese)
\end{itemize}   

\end{document}

Related

• Why babel produce warnings about \rmfamily and \ttfamily with \babelfont
• Mixing Chinese Characters with English (Main Language) in 2019 | What is the "State of the Art"? (my own question)

Remark

• I am in China timezone, so I am a couple of hours in the future for some of you. Keep that in mind when my replies may seem late :).

• I used my fair share of LaTeX in the past years but when it comes to fonts I am really a bloody beginner :). So sorry of the questions seems "stupid" or not well-enough researched.