I use newspaper in the bottom of all my cages and change the paper daily. It's difficult to train two birds who live together because they will have a tendency to bond to each other. It can be done but it takes longer. Clipping the wings does make training easier, but you have to be very aware of the household dangers such as the family dog or cat. Birds will drown in toilets so keep the lid down, and be mindful when you are cooking in the kitchen. Fumes from Non-stick cookware will kill them. Those plug-in scented deodorizers aren't good for them. And people leaving doors open will allow them to escape. Even with clipped wings, parakeets can fly pretty far in an updraft.
I recommend getting a training video to learn how to train birds.
Good luck with them!