and Design take you?
How will I be assessed?
What will I study?
I imagine the way you are assessed varies between exam boards, but generally you'll be assessed on a range of areas including but not necessarily limited to: your use and understanding of materials, quality of work (does it look like it's been done in 5 minutes or did you put effort in?), development of ideas and interlinking your work to a relevant context.
You'll study pretty much anything you want! When I did A-level art, we were given a list of questions that were themes like 'nature;, 'old and new' and stuff like that and we chose one as the title of our project and as long as we could show how our project developed from and related to that start title, we were free to do more or less what we wanted.
I will say that just being technically good at Art isn't necessarily enough to get a good grade. Talk to your art teacher about what you'll be assessed on so they can tell you specifically. I always got very frustrated because I have the technical ability (ie can paint a good picture) but hated developing my ideas and the context stuff.
Also, be warned- it is HARD WORK. It's not like maths where if you haven't done the work you can do it in the morning. If you fall behind it's like a snowball and it can seriously stress you out. If you're thinking of taking Art as a break from other subjects so you have a bit of variety, I'd look to other subjects first. You don't escape from essay writing either
Your A-level choices won't define your life. It's kind of like at GCSE where they make a big deal out of it but no one cares what subjects you take, just the grade. With A-levels, they help if you know what direction you want to go in (like obviously Biology, Chemistry, Physics or Maths would help you onto a science degree or apprenticeship) but there's the option to do foundation years if your qualifications aren't exactly what's required. I think good grades are the more important thing. Take things you can do well in if you aren't sure what to do, you're more likely to be motivated and enjoy a subject if you feel you're doing well. Plus if you take things you're good at and enjoy, surely that leads you to options you enjoy as well? (I wish I had taken my own advice here....)