I don't do architecture (and hence don't work in the field), but I should be able to answer a couple of your questions.
Does the degree contain a lot of maths because it's my weak point?Architecture is more of a design degree than an engineering degree (which I think is what you're thinking). Unless it's a BEng or the degree explicitly states that it requires A Level Maths (there are only a couple of architecture degrees in the country that requires it), then you might encounter a lot of maths.
The level of maths you would require would not likely exceed GCSE i.e. a few geometrical questions here and there. Otherwise, it's more art than anything else.
Which universities have good courses for architecture?I don't have specific recommendations, but what you need to be aware of is that the degree needs to be RIBA accredited. There are roughly 60 courses in the country that meets this criteria at undergrad level. See:
https://arb.org.uk/student-information/schools-institutions-architecture/https://www.architecture.com/education-cpd-and-careers/riba-validation/riba-validated-schools-ukDo I have the right A Levels to take the course?For about 55 degree courses in the country, you are accepted with A Levels in any 3 subjects i.e. you're fine so long you get the grades.
A couple of them require A Level Maths because they focus more on the engineering aspects i.e. the ones you wan to avoid.
There's an odd one that asks for English Lit - I don't get it either, but you have Lit anyway.
If memory serves, there's an odd degree that asks for Art and Design A Level, but you don't have to do this degree since you have a plethora of other choices.
When you make your application for the degree, you would need to prepare a portfolio to show you have the artisitic capabilities to do the course i.e. stick drawings won't cut it. This is usually where the art and design students have an upper hand since they can prepare their portfolio alongside their studies well. You on the other hand would require to go out of your own way to prepare it.
can you use the skills for any other careers?As a design degree, you can use the design skills in other design occupations. Having said that, most art and design careers don't have specific entry requirements i.e. you can have next to no qualifications and still get into the job so long you have the skills to prove it (i.e. you need a relevant portfolio).
Outside of design, you can go into any role that either asks for a degree in any subject all the way down to asking for no prior qualifications. There are roughly 600 careers that meet this criteria, and I am not going to list all of them out in detail.
In my personal experience though, I have come across architecture graduates who just finished at undergrad level; one became a catering manager, the other works as a paralegal. If you don't finish the final exam, then it's not necessarily something you can easily use to pivot to do something else easily. Having said that, there is no rule saying that you can't do anything else after your degree e.g. work in finance, become an accountant, work in law, go into education, do a postgrad, go into psychology, go into economics, etc.
Note, to at least qualify as an architect, you would need to spend at least 7 years in the field; 3 years for your undergrad, 1 year training, 2 year master's (RIBA accredited of course), another year training, and a final exam. See:
https://nationalcareers.service.gov.uk/job-profiles/architect