If you are new to OOP and using windows, I'd suggest VB/vb.net. It's memory managed, so you don't have to bother and with Visual Studio(download for free from Microsoft, just search Google) it's pretty easy to learn once you know the theory behind OOP. As someone else stated, OOP isn't just syntax memorization, you need to understand why things are setup and used the way they are or you won't get very far.
As for C/C++, I wish you good luck. They, by no means, are easy languages to learn, but if you do manage it you will know one of the strongest OOP languages out there
