>>11
I think the "next steps" you want are basically complete, so not really "next" any more. Use the Core Guidelines and their checker tool. The idea here is that this will force you to rewrite old unsafe C-style code to modern C++ and hopefully avoid most of those footguns.
As has always been the case, most C++ code is written inside corporations with a proprietary license. But https://github.com/scylladb/seastar is an interesting open-source project, albeit probably too advanced for beginners. Maybe https://github.com/RainerGrimm/CppCoreGuidelines or https://github.com/LearningByExample/ModernCppCI to start? I don't know, I didn't read a lot of code, I just started writing simple code myself, then reworking it to get past the checker.
cppfront is very interesting to me, but not suitable for commercial use (the NC part of the license). So I'm just keeping an eye on it for now.
For the Rust spec, I was talking about https://spec.ferrocene.dev/