So you want to work on medium-sized C++ Project

Take your time with learning and reading.

Learn git

I recommend reading the book.

Learn how to do the following:

• handling conflicts
• reading the history of a file (git log -p, git log -L, git blame)
• rebasing on main
• interactive rebasing (splitting & merging, reordering commits)
• git bisect

Learn how to use CMake

• Know what it means that CMake is a build system generator and what what the configure and generate steps are and when you need to run them.
• Know what cache variables are and how to change them. (tip: ccmake)
• Know how to do a debug and a release build.

Learn Modern C++

It is a complex language with many footguns. If you don't take your time learning the fundamentals, you will not be as productive in the medium / long run.

To learn,

• Read A Tour of C++ or
• Watch The Cherno's C++ Videos.

There are also great talks on YouTube from CppCon and CppNow, e.g. Curiously Recurring C++ Bugs at Facebook and What is C++.

Also Cpp Weekly has very good videos, e.g. Your 5 Step Plan for Deeper C++ Knowledge.

Also, Driving Compilers is IMHO a nice overview over how a C compiler (and thus, by extent, a C++ compiler) works.

Learn your IDE

• set up IntelliSense / clangd
• Learn how to debug NES in the IDE's debugger

Other nice things

• perf and KDAB/hotspot
• shell scripting / Unix
• Missing Semester

Sustain a Learning Culture

git, CMake, C++ etc. keep on evolving. There is always something more to learn.

Generally, if you learn something interesting, tell your peers about it, they might not know it and should be grateful if they can learn something from you.