Keeping your options 'open' and taking one science won't be useful - if you want to go down the science route, almost all universities will want at LEAST two science subjects. So taking one science won't help you go down a science path.
For the arts/humanities/social sciences, it's a lot more flexible - usually universities will only want one or more 'enabling' subject: a language, maths, English Lit, or history. They also want one essay-based subject (if you did history or English Lit, that would fulfil two requirements - an enabling and essay-based subject). Most Russell Group universities will want you to have two subjects which aren't considered 'soft' - so if you did history and French, that would leave you free to take something else you enjoy at A-Level, even though it might be 'softer'. Go for subjects you enjoy - if you like them, it'll be easier to work more at them and therefore get higher grades.
Since you said you don't really like English Lit, don't feel pressured to take it - history is also an enabling subject, is essay-based, and is what you might want to study. French would be useful, because employers really like having employees who can work with international clients/companies, so is good to have to a high level - and French A-Level includes more cultural studies, so you could also do some aspects of French history! Politics would be good to take too (but I'm biased - I love anything to do with politics
). Geography has aspects of science and maths/statistics, so might show universities you're slightly more well-rounded, although tbh they won't usually care as long as you get the grades.
And remember - what you want to study at university might not be related to your career (unless you want to go down a science/medicine route... in which case your degree matters). Only ~5% of jobs in sectors other than science require a specific degree at university. Go for what you enjoy!