C++ won't import things automatically. If you ever touched a C++ tutorial, you should know what #include is for.

But for associative contains, I don't know of a "good" tutorial, but here's the cppref link: https://en.cppreference.com/w/cpp/container/unordered_map.

The indexing of these maps confuses me, are they numbered or associated with strings or both?

Maps are efficiently indexed by their key. That's why they exist. In general: https://en.wikipedia.org/wiki/Associative_array. For unordered containers, the key can be anything that has operator== and a hash implementation, built-in or otherwise. Common key types are integers and strings.

How does the computer coordinate the data?

Red-black trees. No, you don't need to understand them.