Welcome to the Orchid Board!
That is a nice gift! Fortunately this kind of Dendrobium is not hard to grow. In addition to bull's horns you might find it referred to as an "antelope" or "spatulata" Den. Those terms all refer to related Dendrobiums.
Yours is a small plant. Over time new stems will get longer and longer, with more and more flower spikes. The shorter stem is older.
This kind of Den. likes to be warm and moist all year. It also prefers a lot of light. Where do you live? People in Hawaii and Florida can grow them in the sun as landscape plants. They like most summers outdoors, but should come inside as fall cools. If you grow it inside give it as much light as you can. If you've had it far from a window move it gradually closer so it adapts to the higher light and doesn't sunburn.
The yellowing happens eventually to older leaves, then they fall off. They usually last several years. They also fall if the plant doesn't get enough water. I think you may have kept it a little too dry. The yellow leaf is on the older growth, but I would have expected it to stay green for another year or so. The bark you chose is good. I would expect to water that plant in that bark every 3-5 days, depending on the temperature. Let it get almost dry between waterings. You can tell how wet it is by lifting the plant and noticing the weight. If it's completely dry you can put it in a deep bowl in the sink and let it soak overnight to water. Drain then put back in its spot.
It will soon begin making new growth from the base. When that starts be sure not to let it dry completely, but don't keep it soggy wet. Start fertilizing when new growth begins. You can use any fertilizer with the three numbers like 20-20-20 or 13-3-15 with micronutrients. Mix a half to one teaspoon per gallon of water and fertilize once a week until fall, then go to once a month through the winter.
The next growth might be twice as tall as the one that just flowered, and it will probably have a lot more flowers.
|