It's Detroit, so you have to be smart about things. It's not like you'll get stabbed in the face the moment you step outside, but you need to be aware of your surroundings so you don't get mugged or taken advantage of. Things are pretty tight on campus. There are cameras and guards everywhere to ensure that everyone is safe and that nothing happens to them. You can walk around campus alone, and you'll be fine. But CCS isn't fenced in, so you should still have a buddy walk with you after dark. If you don't have someone to walk with you from the dorm to the 24-hour lab, or any other scenario like that, you can call security, and they will send someone out to escort you to wherever you need to go on campus. It's a pretty small campus, but it's good to know that option is out there. At the Taubman Campus specifically, you can't even step foot more than 10 feet inside the building without showing your ID or having someone sign you in as a guest. The parking garages on each campus also require an ID to get in and out.
As far as health goes, CCS offers a health insurance plan to all students. Students are automatically covered by accident insurance in case they get hurt on campus. If you decide you want to purchase extra insurance in case of colds or flus that might come about, it's a very reasonable price. At orientation, they will normally hand out a packet that you can choose to fill out if you're interested. There is also a nurse on staff in the Student Life Office a couple days a week that can help treat you and officially excuse you from class if you are legitimately sick.