If you are just starting out with Copic Markers then this video may help to answer some of your initial questions. A summary of what is covered is detailed below:

How Copic Markers compare with Stampin up Markers

Which colour Copic Markers you should buy

How to use the Copic Markers colour chart to help you choose your colour pallet and avoid buying duplicate Copic marker colours

Summary of the differences between Copic Original Marker, Copic Ciao Marker and Copic Sketch Marker

Advice on which inks work well with Copic markers when stamping

Examples of which papers work well with Copic Markers