Do I have to replace the hub or cassette? Or both?

I bought this bike not long ago (used) and just took it for its first ride. I noticed that when the small gear was engaging it was just spinning and skipping heaps, the whole cassette was also very wobbly. I took the wheel off and realised that the part where you’re ment to put the removal tool is completely sheered off, and all I had to do was just pull on it and it took the hub bit with the clicky wheel thing with it. All the bearings also just fell out. Is any of this fixable? I’m still very new to all this, any help is much appreciated!

by Dankleaves