Don't know why I'm on this forum, but I have an LLB, LLM and I'm currently doing a PhD. All in law.
If you want a practical introduction to the study of the law, I'd probably suggest "Laying Down the Law" 9th edition. You'd probably be prescribed that in your 1L Foundations of Law unit anyway. This will give you a solid introduction to the study of the law and isn't too technical.
As to specific areas of the law (contract, tort, criminal) the Nutshell series is a good, cheap option. "Nutshell: Torts" 6th ed & "Nutshell: Contract Law" 7th ed would be two good options. You can get those two brand new for only $35 each. I see Laying Down the Law is listed on LexisNexis at a shocking $96 (was more like $45 when I was in 1L what seems like not that long ago). You'd probably be better off consulting this text at your nearest university's law library... Just walk in one day and find it on the shelves. As long as you don't try to steal it, staff won't kick you out for being curious! So there's three good recommendations for you.
I think it's commendable you're looking for an actual insight into what the study of law will be like. The To Kill a Mockingbird reference did make me smile, so many people have said they wanted to do law because of that book, but as you can imagine it's not really a good insight into what the study will really be like. Do you have moot court as an extra-curricular activity at your school? If so, I suggest checking that. That would be a good bit of experience. Apart from that, you're just going to need a high ATAR. Best of luck.