This is definitely not a dragon fruit plants, pitaya, Hylocereus undatus. The dragon fruit plant is more cactus-like with fleshy stems. The plant is easily started from stem cutting if you know someone that has one. The stem is placed into potting soil and roots very quickly.

I have attached a picture.

The one in the picture has been trained to grow one stem on a support. When apical stem is tall enough, usually to the top of the support, cut the stem to encourage branching.