How to do well in Cambridge CS interview

Basically, I just want to know if I have to be super smart to do well in my interview - I know the CS interview is going to be very maths heavy, and while I'm not downright stupid, I wouldn't say that I'm maths genius kind of smart, just pretty average. If I show how much I really care for the subject and that I am teachable etc. do I still stand a chance? Or are they expecting me to be a whizz at maths kind of person

Do they expect you to know some interesting stuff on computing/things related to computer science or is it sufficient to read a few articles based on computer science that would be fine to mention in the interview? Also how much of the personal statement matter sin the computer science, and in general, STEM interviews?

I would like to preface this with the fact I am not a CS student but a NatSci one so maybe take this with a grain of salt.
Generally it is nice if you've read about something that isn't in the content you have/will learn in your alevel/equivalent course, and sometimes (depending on your interviewer) they may use it as a jumping off point for the rest of the interview if they find it interesting enough or just a simple introductory question. How much reading you want to do is up to you, but I would say having one topic that you've delved into would be better than a surface level reading of many topics.
On personal statements, I've thought of it as, if there is something interesting that you have wrote about in it, they might bring it up (so make sure you've actually read what you say you have before the interview) otherwise for an interview maybe not so much.
Do beware that I didn't do anything interview for the same course or for the same college, so things might work slightly differently