You need to learn C in depth and than try your luck with RS 232. Than you may send some bits to the controller and get some back.
Start with some video
RS 232 tutorial and search for more.
You must also understand threading because that interface is serial and so after sending some commandos you may have to wait for an answer. Here is good
overview and some sample code.
PS: I have done this nearly 20 years ago, so believe my experienced tips