beginner C++

[Marvin GodfatherofSoul Bellamy]

I'm a Java programmer, but I figured I'd better learn C considering the 
market conditions.  I'm used to the rich centralized API that Java 
provides.  My question is are there equivalents for C users?  I'm 
thinking of classes (whatever C calls them) for making network 
connections, GUIs, etc.).  Keep in mind that my knowledge of C is 
limited to the basic comp 101 programs.