It says if you are going to have more than one mouse, you should either have a male and a female or two or more females in one enclosure. Males kept in the same enclosure may become aggressive. Any type of enclosure is fine for mice as long as it has a lid and plenty of ventilation. The suggested bedding is aspen shavings. It is important to change the bedding and thoroughly clean the enclosure with hot, soapy water on a regular basis.
Mice like to have something to make a nest in.
A small empty facial tissue box works well. It will probably be shredded into bedding, but it will serve as a good disposable hideaway. Empty paper rolls make great tunnels for playing in and shredding. Exercise wheels having solid running areas are suggested for mice. Anything with open rungs can cause injury if the tail becomes caught.