How did they managed to pull this off so quickly? Given how long WebGPU native is in development and still not finalized, you would think it will take SDL GPU API even longer because it supports more platforms.
"No prototypes. Just make the game. Polish as you go. Don't depend on polish happening later. Always maintain constantly shippable code." - John Romero
1. Modern C++ is obviously a huge topic but if I had to describe it in one sentence I'd go for "use smart pointers and containers instead of raw pointers and raw arrays" or "c++ is more than c with classes". If you are completely new to C++ I would recommend "Professional C++" 4th or 5th edition by Marc Gregoire. After that read everything by Scott Meyers and Bjarne Stroustrup you can get (released after 2011).
2. You could use Bazel. Also look into CMake, it's an industry standard, so to speak, and will let you generate build files for almost any kind of build system including Makefiles.
3. I don't use any but some people have success with vcpkg.
4. Clangd is a good choice.
5. A quick one that works is VSCode + clangd and CMake extensions. Clangd will let you format, lint and do some basic static code analysis. Installing clangd extension will install clangd automatically. Or, if you are on Windows, "Visual Studio: Community edition" is even easier to start with right away.