Is there an easy way (like a free program) that can covert c/c++ code to x86 assembly?
I know that any c compiler does something very similar and that I can just compile
Your compiler is already doing that as you've stated, and most likely will have an option to stop before assembling.
For GCC, add the -S flag.
-S
gcc -S x.c cat x.s
Edit: If your program is pretty short, you could use the online service at https://gcc.godbolt.org/.