Can I ask exactly what course you're doing at La Trobe? I had a look at the undergrad law course and unfortunately you guys don't seem to do a legal writing/research subject like we do at Monash.
Definitely go to lectures because unless your lecturer is totally useless, they will generally summarise the cases you have to know into easier-to-understand language. Tutorials are more for learning how to apply the principles you have learned to a fact scenario which is absolutely essential to know how to do.
I would have recommended doing 3 instead of 4 units a semester regardless of your English skills. Four law subjects is really time-consuming and high pressure and I do not recommend it for anybody unless they don't plan on having a job or a social life during that semester.
What do you want to do with your law degree? If you want to become a lawyer, Ps aren't going to get you anywhere. It's already a highly competitive industry and since you are not going to a Group of Eight school, you'll need to aim even higher.
Otherwise, have a look here for some ideas:
(by request) What can I do with a law degree?