I'd suggest you to first learn the basics on your own. If you know php, then you do know something about C++. (The syntax of php and C++ has some similarities.) After you understand the basics, go and find an open source projcet and participate there. There's lots of opensource projects which need help, and in which the community is wery tight, IRC channels, forums, bugtrackers, VCSes already formed. That allows co-opration far better than any other way you can easily think of. It is extremely clumsy to try learning together if messaging channels are a forum and email/instant messenger only.
Just my $0.02