So, I'm a neophyte to the houseplant world and it turns out I'm a terrible plant dad. This is my first apartment and I love having flora about the place but need help with proper care. I have several plants, but will focus on the two palms for now.

1) Majesty palm. I bought Drew from Walmart. He was roughly 5.5 ft. tall and very lush. Since then, he has lost upwards of 70% of his fronds. I had to remove several because they turned completely orange and dried up. He's down to one fully developed frond and two new shoots now. The fully developed frond bent in half from its weight, so it's being propped up currently, but is beginning to sport browning fronds. I also noticed that even the stems of the shoots, as it attaches to the trunk, are turning brown. I think I was over-watering him to begin with and the soil didn't have proper drainage. I repotted him with a different potting soil as well as palm food and have cut back his watering but he doesn't seem to be responding. I think he's on his way out but would love to save him if possible.

2) Cat Palm. I bought Donna from a great green house near my apartment. She's roughly 6 ft. tall and 4 feet wide. Still fairly health, next to my west-facing window. However, the majority of the fronds on one of the branches are turning yellow, starting from the tip. I wasn't sure if I should be concerned with that. I know yellowing can be an indication of over-watering but I've only had her for two weeks now and watered her once. I haven't had the money/time to get a legitimate pot for Donna, so she's still in her little plastic container but it has great drainage.

I desperately want to be a good plant dad but can't seem to help these things flourish. I would appreciate any advice you all can give! I can provide photos if needed.