Can you take a little closer picture? It is hard to tell if there are spines or just some sort of nodes along the branches.

From here it looks to be Selenicereus testuda aka dog tail cactus. I’ve owned this once a few years ago and killed it. These are more of a tropical type cactus, so one cold wet winter destroyed mine:(. I can’t tell you much, but do not treat like a stereotypical cactus, dry and lots of sun. I would stick with morning sun or bright filtered all day light, fast draining mix, and I’m not going to tell you when to water because I don’t know your environment. In my dry summer environment I would water it really well once every five days:).