Hello, google couldn't answer so now I'm here. I didn't buy my class textbook and instead am using C++ Primer, however I just noticed it's teaching C++11, should I pay and get the newest version?
I'm not in the best financial situation, but my grades and education are far more important for me.
C++11 is still relevant. Not all compilers implement the very latest features anyway. If you can't afford the latest edition you don't have to get it. Once you have a solid foundation you can pick up the new features later on.
No, it is still a good book to start learning C++ with.
Most of the significant additions to the language are in the standard library; and you wouldn't be needing those initially. In any case, as yet, there is no text book that covers C++17 (AFAIK) and there is no compiler vendor who provides a complete C++17 implementation.
cppreference.com http://en.cppreference.com/w/cpp has an up to date C++ reference; if required, use it to supplement what's in the book.