There are quite a few ailments your phal with the yellowing leaf could be suffering from, and I'll leave it to more experienced growers to speculate, but I think all would agree that you need to use a sterile cutting tool and remove that damaged tissue. It will continue to spread and infect your whole plant, regardless of how it acquired the infection. Cut 1/2 inch into the healthy leaf tissue and rub the cut with neosporin, cinnamon, or sulfur. Believe me, your phal will survive the surgery fine and will even thank you for it!
As for your second photo, I'll be awaiting some advice from other growers along with you and WELCOME!! You will LOVE it here!