What should I do with Arduino starter kit?
There many brands of Arduino starter kit, but most of them contains the basic parts such as: couple of leds, some resistors, diodes, and perhaps a servo engine or a 8-bit shifter. 

The purpose of those kits is to put you on the right path as a beginner; They usually include a hard copy/PDF book with some circuits you can create with the parts they contain. 

The real question is - do you want to make something specific? Or, do you just want to have a starting point. Usually the resistors and other parts supplied with those kits fits the circuits described in the attached book, so if that's your intention, you should be good to go.