Hello,
to program device in C/C++ you need a processor. You have written that you are going to program FPGA device, but you've written nothig about your hardware (the FPGA board type and vendor). You can use either hard-processor (for example some kind of ARM CPU in SoCs) of soft-processor like "Microblaze" or "NOISII". Depending on your hardware platform (FPGA from Xilinx or Intel) there are different tutorials how to program these platforms in C/C++ language.
Regards