Applying to US colleges from the UK

I think the first step you need to undertake is to identify how you will pay for university in the US. There really isn't too much point considering it further until you know you can finance those studies. You won't get funding from SAAS or SFE to study in the US, and as an international student you won't be eligible for the US equivalents of those funding bodies. You will also need to pay international tuition fees, which are enormously expensive.

Your grades and EC profile pretty much rule out any need-blind universities (as these are the most competitive "elite" college, e.g. Harvard etc), so you won't be able to get the university to fund you in that way. You likely won't be eligible for any of the few and far between academic merit scholarships, so really the only possibility I could see would be a full sports scholarship - which you will probably need to already be competing at a county (minimum) level, if not nationally or internationally.

My parents have said they’d be able to mostly support me financially but was hoping to get a scholarship, even if it only pays a tiny amount as it is really expensive. And I haven’t done any sports in over a year so I can’t get a sports scholarship.

I'm not sure you or they fully appreciate the costs of university in the US, as unless your parents are literally oil barons I'm not sure they will be able to support you. Tuition alone is usually about $30k a year if you're an out of state US citizen or an international student, and it's usually higher in some majors for international students (e.g. STEM subjects). You are almost always required to live on campus in university accommodation (as in, you are not permitted to graduate if you don't), which is usually about $10k a year minimum.

These are not exceptional values; they're pretty average. You're also normally expected to buy books etc for your courses, unlike in the UK where you are rarely required to purchase any books, and they normally require you purchase the newest editions which are the most expensive (and which means you can much more rarely get a second hand copy from other students). Books alone can cost over $1000 a year.

It really is an enormous financial commitment, even for fairly mediocre universities in the US. I would recommend you look at other universities in the UK which will allow you to be funded by SFE or SAAS. There are plenty of options which would allow you to study fairly far from where you live right now, if that's what you want (including, technically, in another country, as you have four to choose from which you will be funded in - Wales, NI, Scotland, and England). Alternately, university in Europe is normally much cheaper than in the UK, where often you just pay a nominal administration fee and otherwise your only costs are living expenses (rent, food, etc), and further afield than the UK at least.

US Universities do have incredible financial aid. About 100 offer financial aid to international students, not just the famous ones. If you apply to Yale as an international student and your parents earn under about £65k, they'll pay everything - books, tuition, accommodation and even airfare and a laptop.

OP is not going to get into Yale or NYU, or indeed any need-blind college, with their academic background and limited ECs. Realistically, they are looking at full ticket price colleges, which as noted are extremely expensive. Contrary to your assertion, outside of need-blind colleges (which are the most competitive in the country, and usually even more competitive than Oxbridge in the UK), there is extremely limited financial aid available in the US for international students (in fact, also for domestic students)