University requirements

You don't need a portfolio lol

Just take Maths, Further Maths, Physics and Chemistry at A level and try to score highly in them. If you were applying now then you'd want to be getting 90% or higher UMS in your AS's, but since you're in year 10 I imagine that they'll have scrapped AS levels by the time you start so I'm not sure how you could show that to them. I think Cambridge are introducing entry tests though, so try to do well in that and practise your interview technique.

Edit: Wider reading helps too (to show interest and increase your general understanding of the subject)

You don't need a portfolio lol

Just take Maths, Further Maths, Physics and Chemistry at A level and try to score highly in them. If you were applying now then you'd want to be getting 90% or higher UMS in your AS's, but since you're in year 10 I imagine that they'll have scrapped AS levels by the time you start so I'm not sure how you could show that to them. I think Cambridge are introducing entry tests though, so try to do well in that and practise your interview technique.

Edit: Wider reading helps too (to show interest and increase your general understanding of the subject)

they say that if I need to get into a good uni, I need to do extra curricular activities..

I presume "they" are either ill-informed friends or teachers who are trying to motivate you to behave well or take on extra chores (aka being a prefect). Some universities are interested in non-academic, non-subject-related activities, but not many.

So Cambridge or Imperial does not require extra curricular activities?

Thank you! Ad if you don't mind me asking, do you do physics? I was looking at molecular physics and was quite interested i that. Also, they say that if I need to get into a good uni, I need to do extra curricular activities..

Who said that? Your school advisers? They are usually full of ****. Extra-curricula activities can help but to suggest you need them to get into university is lying and placing you under undue pressure. The most important thing is that you do well in your exams. That being said, for a portfolio it's probably best to include stuff directly relevant to the subjects. That doesn't mean pop sci books with absolutely zero technical content, but competitions like the olympiads, any externally organised projects like the nuffield bursaries, stuff like that.

The teachers and some of my friends told me I HAD to do at least one extra curricular activity!!

I'm currently in my last year of A levels, but I do study Maths, FMaths and Physics.
Personally I enjoy particle physics a lot, although at A level it's only very basic stuff (which is why wider reading is great!). Buy a book on molecular physics and see if you enjoy it
I'm actually hoping to study Economics at university though, but I'm quite strongly considering taking a gap year atm

And no, you don't really need extra curricular activities at all, most of the good unis care much more about your academics than whether or not you have a grade 7 in the clarinet lol
I got an interview at Oxford (didn't get in sadly) and the only extra curricular things I mentioned were things that related to the degree, such as doing well in the maths challenge for example. The only non-academic thing I put was getting to the gigafinal in the chess challenge because it seems relatively intellectual haha

(If you apply to American unis though then they care MUCH more about what you do outside of school so that's something to consider)

What books would you suggest if I would like to broaden my knowledge on physics and chemistry?

Have a look at the website for some courses which you might be interested in - eg chemistry at Imperial - and see what they say their entry requirements are.

Cambridge make it very clear on its website, as does Oxford, that it takes no account of unrelated non-academic activities whatever.

A book on particle physics that I've read which was great for learning the basics was 'Particle Physics - A very short introduction' by the Oxford University press (they have a whole series of 'very short introductions' so you may want to browse some). Another book I bought was 'A Universe from Nothing' by Lawrence M. Krauss (more of a physics-philosophy book but some great stuff about cosmology in there). I'm not sure for molecular physics but have a look on Amazon and you'll probably find a few which catch your eye

Wow!! Thank you so much!!