bluetooth-serial-port VS terminal

Bt SPP protocol is quiet universal and you can use it for whatever you want. It's just like normal serial line. You can transfer files, control something, etc... I found this library https://github.com/Agamnentzar/bluetooth-serial-port maybe it'll be helpful for you.

If you decide on directly using the lower-level Winsock2 API, you aren't really going to get much out of the official Microsoft documentation; it's pretty lacking, as you have noted. Instead, I suggest taking a look at the Network Socket Terminal source code (Disclosure: I'm the author of the software). Specifically, these sections:

I'm currently using C++ for a network communication app. The language's predecessor, C, has had a long, distinguished history in computer programming, and thus it has many APIs written for it. In networking, for example, you have POSIX sockets and Winsock. C++, being a superset of C, allows you to directly call these APIs in your code (and there have been C++-exclusive network implementations as well, such as Boost.Asio and the upcoming C++23 Net TS). This gives you a lot of flexibility over what you want to do, as well as how you want to do it. Other high-level languages, such as Python and Java, may also have similar capabilities, but they're basically just using C/C++ internally. Occasionally, those language bindings might not even be enough - Java, for instance, doesn't have a remotely good Bluetooth implementation (while you can use Winsock/BlueZ in C/C++).