I recently bought this ph

al at the grocery store. I haven't watered it yet, and I don't know what kind of medium it has. I assume it's on sphagnum moss. But it has been having yellowing leaves (I've already cut two off) and it has dropped two unopened buds (this am I found another, in addition to one I found yesterday). I moved it closer to the window in case it wasn't getting enough light. Should I repot it? Or water it? The other leaves look ok. But something must be wrong to have bud drop. My other phals like it by the window, and one is going to have more buds soon, and is putting out another plant. So thank you to whoever suggested that I put them by the window.