UCL Arts and Sciences Watch
There are quite a few threads on Arts and Sciences on here with some useful information.
I would definitely say that the Core is not mainly science - most people would say it falls more on the arts/humanities side - though some modules are more science oriented. For instance, Quantitative Methods does have some element of maths in it, but it's definitely more about the application of maths to the real world, and very much oriented towards people who don't have much maths experience.
It's helpful to have some interest in science for sure since there is a requirement to take at least one module each year which is quantitative, but it doesn't have to be your main interest. Maybe if you say which subjects you are interested in, I could try and give some information based on that?