Hello :-)
Yes, you are right, most C++ compilers (and other Langs. e.G. Pascal) allow inline Assembly, but they don't allow the acces to registers and system-calls (atleast I was never able to find that out.)
For the first time assembly, it might be better to use
nasm, ld and for debugging GDB.
If I'm wrong tell me ;-)
Enjoy my programming challenges, linuxer4Fun