I'm doing Sociology and Psychology.
With Sociology, you do need to remember some key concepts and names of sociologists. There is essay writing as well but it's interesting to look at all the different perspectives like Marxism and to learn about society.
With Psychology, as previously stated, you do need to remember some key studies. There is also evaluation you have to memorise and again essay questions. There is also math included but it's usually to do with statistics like sampling techniques, means etc. People got advised to take Maths at A level alongside it but I didn't and it seems to be going okay.
I would advise looking at the different specifications and seeing what they cover and their markschemes. You may not know your exam board but you could take a glance at AQA or OCR to get a general feel of the subject. You could always just wait and see how you feel about the subject as you study. It's early on so if you don't like it, you could substitute it for another.
Hope this helps!