Well I am learning about curves. I have come across Bézier and Spline curves. I want to know which one should be learned first? Are their concepts independent? or I need to know about one before learning the other?
Bézier curves are more fundamental, so I'd suggest that you study these first. A b-spline curve is just a string of Bézier curves joined together, usually in a nice smooth way. So, understanding Bézier curves will help you understand b-spline curves.
A good place to start might be these notes.