It looks like there are a few expansion kits for that robot, have you looked at those?
Alternatively you could expand and add on to the robot or build a new robot perhaps using some of those components.
The question is what do you want to do? What are your interests, mechanics, electronics, software, etc.? What would you like to make the robot do?
I recommend you start small and work in steps; for example, if you are interested in electronics you can add new sensors or if you are interested in mechanics you could ad a gripper, etc.