I don't do history so I can't really say much, but from what I've heard, it really depends on the person. I guess if your good at essays (making good points and backing up with strong detail, context, analysis etc) then you should be fine. I think history also has a pretty consistent marking criteria/answer structure but I'm not too sure.
Right now for me geography is easier as it's just learning and memorising key processes and facts. The thing about geography, it's basically just memorising the key content and case studies.
And for computer science, I think its pretty much just knowing the main content (and for coding, just practicing it), which you can build upon. For example, I do AQA computer science, and our school picked python as our programming language. At first I found it hard knowing my way round it, but with a bit of practice, it certainly does get easier.
Sorry idk anyone who does both cs and history
Currently, I'm getting slightly better on geo than cs, purely because it's just memorising the content as well as using common sense. For cs, idk for ocr, but for aqa, some exam questions require you to write code in pseudocode and python, so if your good at this, you'll be fine on most of cs.
But just to summarise, I think history is mainly based upon source analysis, and geography is just memorising key content and case studies. Also I think some parts of geography is just common sense. But as I said, if you find geography boring, it could make you feel unmotivated to revise for it, plus if your finding history more interesting, it could possibly be a bit easier for you. And for cs, I think its just mainly practice, and knowing the other content. Idk too much about history, so don't fully rely on what I said, but in the end it's your choice of what you pick