- When should I start studying? I'm a really big procrastinator
And how long should I spend studying each day.This is really up to you and your habits at the moment. If you don't like them, change them bit by bit. Don't be drastic.
Also, as a big procrastinator myself, I can personally recommend you check up productivity apps to stop yourself going on unnecessary sites and stuff. On that note, I'd say getting the best out of planners/ school diaries are best, because it's made for a reason. I still procrastinate a bit, I'll admit, but you can always fine tune it over and over again. However, do what you think is best for you and chill.
- Any good websites with information? I don't want to go spending money on VCE practice books 
I didn't really buy any for Unit 1 and 2 subjects, really just 3/4 subjects. Don't worry. I would advise AGAINST using VCAA practise exams until the end of your Unit 3/4 subjects. Searching it up on Google is usually helpful. If you're doing English, there's a multitude of resources online. Same goes for Maths, Sciences and well... most subjects. Borrowing from a family friend or relatives who have done it also helps and your library (local and school) may be the hidden treasure trove you're after. Talk to your teachers and I'm sure they'd love to help find extra stuff to practise with as well. (Best of all, it's most likely to be FREE!)
- I think I might want to be a clinical geneticist OR a business lawyer when I'm older (I'm really torn). Any advice? And also, what subjects should I take to become a clinical geneticist/business lawyer?Probably study a diverse range of subjects that will lean towards these. Something like Chem or Bio, paired with Legal Studies or Business Management sounds like a way to go. Definitely check up VTAC Course search on Google and see the pre-requisites, and do those subjects.
Don't forget to have a bit of leeway though, because you may end up wanting to be something else in the future. (When I was in Year 9, I wanted to be an architect. I gave up after a while, because I realised I didn't really like it.)
I tell a lot of younger students to choose appropriately for what they're considering and get a general overview on the pre-requisites on VTAC Course search before they choose. It helps to be broad and it helps if you have all the general pre-requisites. Some to consider: English (duh), Methods, Spesh, Further, Chem, Bio, Psych and LOTE subjects. These are some of the wider subjects that you might use as a middle-band (basically up your position when it comes to university/ other institutions) or pre-requisite.