Need lots of help with cats

First of all I am new to cats. I just got two in the past week and I am not sure if I am doing right by them. I keep them strictly indoors except fro today when the youngest one (Peanut) escaped.
My oldest one, (Popeye) is 6 years old and I realized yesturday when I got home with the kitten that he had red runny eyes and sneezing. I am concerned because he will not eat the cheap food that the humane society gave me when I adopted him. I have bought Eukanuba hairball releif because he was throwing up alot of hairballs and also some moist cat food. The thing is he is not eating that well either. What can I do, I have locked him in the bathroom to keep him seperate from my other kitten and he liked it in there anyways.
My second concern is Peanut is only 9 months old is not eating anything. Should I put him on dad's cat food because that is what they were feeding him or she would buy him kitten food and what kind. Please I prefer to give moist food a few times a week but I want to leave some kind of dry food out all the time so they can eat when I am at work or away from the house.
Sorry so long but I am worried they are going to starve to death. Thye both drink water that is available at all times.

Sounds like you have two ill cats and you should get them to the vet. Once they are diagnosed and on meds things should improve. You should not be switching foods suddenly on them, you need to do it gradually or they will get diarrhea. But really, they both need a vet and your vet can guide you to the proper food-

I agree with MA you need to get them to a vet and see whats going on.

It sounds like upper respiratory infection and he is not eating because he can not smell the food. They need to go to the vet on get on some meds, it clears up quickly with the right meds.

VET also ...