Removing a spent spike is quite normal. Once the inflorescence has died, there is no value in leaving the spike.
You didn't specify how you are growing your orchid so we've got little to base a response upon. An occasional yellow leaf is not uncommon, but if all are turning yellow it would appear there is a problem.
The first thing I'd recommend is go buy some new potting media from a good orchid supply and repot the plant that is failing. Probably best to repot both. Orchids should be put in new media each year since fungus and other detrimental elements can build up in the old media. Orchids do not grow in "media" in the wild. They grow attached to a tree branch or limb with their roots simply hanging. But in captive growth, the media helps to give the plant a constant supply of moisture.
That new media should be kept constantly moist. Misting the plant may also help. Add a small amount of orchid fertilizer (perhaps 1/4 teaspoon) to a spray bottle. Remember, these are rain forest plants. They love to be damp and humid. Your plants will also appreciate bright indirect light. Most new growers often give them inadequate light that is insufficient to allow the plant to thrive. Since you are in Canada, keep them away from a cold window when winter sets in.
Orchids are generally easy to care for if you are willing to give them what they need to thrive. I'm giving you a link which may help with other advice. Once you read this, you may have additional questions. There are several very good orchid growers on this board that give excellent advice.