Jujubes are a very easy to grow tree, they'll survive the extremes of weather in a New York-ish climate without any special protection, unless the trees are young and too fragile without burlap or covering of some sort. Waiting for them to give fruit will take time and patience, but these trees thrive on neglect and will give more fruit than you know what to do with. As long as you put them in decent soil, give them some compost and nice mulch, and keep them weed-free, after the first year or so of caring for them and watering them, you don't have to touch them whatsoever and they'll live for years and years. Just make sure you mow down root suckers the second you see them and prune the trees if needed. I've had a Tigertooth jujube for 2 years and it hasn't given me any fruit yet, but it's survived pretty terrible conditions.
Now frukt, you should know that jujubes taste okay, not amazing but okay, and only some varieties are recommended for eating fresh. The rest of them are meant for being dried and stored for use in teas, baked goods, medicine, etc. Without cross-pollinating jujubes, there won't be as much fruit, and they might not be as tasty. It's why nurseries suggest you plant Li and Lang, Li is only partially self-fertile while Lang will not give fruit without another variety nearby. The fruit has to be picked in the morning before the sun shines strongly during midday or else the fruits will be shriveled and have the consistency of styrofoam.. you want to pick them while the moisture in the tree circulates to all the fruit, you see. And to make matters even more confusing, certain varieties taste different depending on the weather and the climate they're in! The fruit from one tree will taste different year to year depending on the weather too, according to what I've read.
If I were you, I'd buy an already established/ possibly grafted tree to save yourself time and money. I'd do more research on the varieties you want and how they do in your climate, I could give you good suggestions if you give more details on the growing conditions you'd be able to give them. I myself am testing out how my jujube tree does in NYC and I'll eventually graft more varieties onto it once it's old enough to bear fruit without any special attention.