Hardware for simple Robot

Hello,

I'm new to robotics and I can code in C++.

I want to make a simple Robot for my Cat.

It should do some tasks I code on my Raspberry Pi.

First of all it should activate on a defined time of the day.

And it should be powered by batteries.

Second: It should navigate based on 2 axes.

I want it to swing a stick horizontal at a maybe 30° angle. And it should vibrate.

Now the question: What Hardware do I need? I already have a Raspberry Pi and I will build a Case at my own for this.

Thanks for your help!

PS: English is not my main language. So sorry for faults.