Hi Paul...it is, indeed, oak, and a good attempt for a first box; the finish on the end grain looks spot-on.
I well remember my first turned box, just several months ago. The concept of turning boxes really appealed to me and I can still remember just how much time (and concentration) my first one took. I still really enjoy making them and it's great to see that they are popular things. Keep at it...keep practising and get them deeper....practice pays off!
Well done for a first attempt....Les