Don't worry about what you will have to do in the future. Just focus up on your courses at the moment.
A lot of majors require students to stay longer than 4 years to complete their Bachelors not just the engineers... though I believe engineers need to take more units than others (I'm a CIS student)
Don't be intimiated by the stories about how hard engineering is, because it should be hard. CPP is a great school for engineers because it is known for producing engineers that go on to work for big well known companies.
That being said, CIS is part of the College of Business. Computer Information Systems at CPP has different focuses like App Development, Security, and Business Intelligence. Essentially, CIS gets you a job in IT. Depends what IT job you want because its quite broad.
Lastly, my opinion: Based on your post, it seems like your a Freshman. Nothing wrong with that. But my advice is to, as the first bullet point goes:" Just focus on your courses at the moment." Stop worrying about things in the future that you can't control at the moment. Also, you got admitted to CE, so I guess the school believes you are fit for being a CE student. But I think it is still to early for you to switch majors. Also focus up on the math and best of luck.