hi! year 11 student here
i do business AQA, and i personally don't find it very hard (though that depends on each person individually and how good the business department at your school is)
if you're good at following and remembering structure (like PEEL in english, or whatever acronym you use at your school), then i think it wont be too much of a struggle. in terms of content, i'd say there's quite a lot but it's about the same amount (or less, i cant tell) as geography gcse, which i also do
personally, if you don't really like business then you might find it a bit boring, but that wont necessarily stop you from getting good grades in it. if you have to definitely choose between either business or geography, based on your post i would say geography. i dont think ive learnt very many transferrable skills from business, because it's really just a lot of memorisation and application.
also, if you want to do business in the future then you dont really need the GCSE for the alevel (though i would definitely do your own research because i've just done a quick google search). i have a friend who's sister didnt do the alevel or the gcse, but somehow does it at university? not sure how that works, but you wanna go the same route then definitely do more research.
if geography is something you wanna do in the future as a career, then definitely choose it at GCSE. idk how it works at your school but in mine you need the GCSE for the alevel, and I would assume maybe also a university degree (though i havent checked this so dont take my word for it)
always remember that you always can (and should) switch your gcse options early in the year if you realise that something isnt a good fit, and you shouldn't stick to one of your options out of embarrassment or fear of inconveniencing someone. if i could go back to year 9 and change my gcse options, i definitely would've chosen computer science, but i also understand that i couldnt have possibly known that i would've wanted to do it now. it wasnt a mistake to not choose it, but it was a mistake to not change, or think very hard about changing, when i started feeling unsure.