Phalaenopsis afflicted with yellowing leaves

[OakRidge]

Hi everyone,

I'm a beginner orchid grower (on my first plant!) which is a Phalaenopsis hybrid. I received it as a gift about 1.5 months ago and it was doing quite well for awhile. It had two stems but one dried up which was mildly alarming, but I didn't know what to do about it. I thought perhaps it might be normal as the other stem was still very green. The plant has also had two of its bottom leaves yellow and fall off, which I read are normal for bottom leaves, but now one of the top leaves is a bit wrinkly and appearing to yellow (in spots!) but the other top leaf is very green and looks healthy. It's in a pot with bark at the bottom and moss at the top. I put in on my dining room table which gets sunlight from a West window that is mildly filtered, and I water the plant every 10 days or so by filling the pot with water, letting it stand for 10 minutes, and then draining the water.

With that background info, I have a few questions:
1. Was that normal for the other stem to dry up like that? You can see it in one of the attached pictures. Now that it's dried up, should I cut it off?
2. Should I be alarmed that one of the top leaves is wrinkly and getting a yellow spot? What might be the cause? I've done some reading and it may be a symptom of rotten roots? What is the best way for me to examine the roots without damaging the plant?

I apologize to avid orchid growers who might think that I've done a disservice to this orchid! Admittedly, I don't have a very green thumb, but this orchid was beautiful and I would really like to learn more about growing them. But now I think my orchid is in trouble and need help! Thanks for any advice you can give