I think if you look for "parsing documentation" then you'll be up to your eyeballs in technical details that you don't need to know.
Raw C++ has no "parsing" built in. It all depends which library for file handling (and optionally, for string handling) you choose to add to your project. If you do it with e.g. iostream + std::string then you need to write a low-level state machine and your own data structures. This is very flexible, however, it's also brittle in that if the file structure can deviate from the expected structure, you need to write your code to take account of all the things that could go wrong with poorly-formatted user files. So, you end up with very complex code with tons of if-statements, special clauses, error checking at every stage, and it only gets more complex and more "spaghettified" as you add in more types of tags, nesting, or tag parameters that can exist.
Basically, if you want to avoid a massive time investment in making your custom parser work just-so, then your best bet is to use some pre-existing file structure, and grab libraries that can read it. XML or JSON are the main choices. I prefer JSON as the main choice, since I know that PHP and JavaScript both have built-in commands for reading/writing data structures to these files. The advantage is that a JSON reader can turn the "raws" file straight into a data structure in the programming language without needing any "manual" parsing from your own code.
If you want something that's more hands-on in giving you more control over how the files look, I recommend that instead of writing your own parser, you get a Regex library for C++. Using Regex's instead of manual parsing would save a lot of work, and Regex rules are far more robust than what you can probably code by hand.