DnD - If you want to try your hand without spending a lot of money....go buy a cactus with the stupid colored cactus graft on the top - if you find one on sale, so much the better. Rip top off and discard the top - very hard to get it to root. Grow the base cactus in cactus mix or 1/2 potting soil and 1/2 sand. That is a cheap dragon fruit. In your zone it will be slow going. To speed it up, move outside in summer. To get to fruit producing size, they grow huge - 8 - 15 feet. Doubtful in your zone you will see a flower or fruit.
I started mine in July or so from one bought for $ 4 at Home Depot. It has two branches about 14 inches long each and they both have made air roots.
