If you either don't want to or cannot use Visual Studio for working with the C++ project, VSCode is a good alternative.
The clangd extension is recommended and requires clangd to be on your $PATH. If you can run clangd in a terminal successfully then you should be good to go.
Once you generate your CMake for the first time the clangd LSP should be able to index the project and give you intellisense.
TODO - Consider Contributing Documentation :)