People say there's no point - and I was one of them who didn't do a lot of outside-lecture work.
I really regret that now going into my third year.
My best advice would be to look through your lecture notes and try to consolidate your whole lecture onto one side of A4 - that way you can look at a glance the information the lecture gave to keep it in your memory, and then you can use notes made in lecture and lecture slides to give a much better understanding.
I never did a lot of reading and I partly don't regret that (I hate reading), but if there's a concept you struggle with it's best to do some relevant reading for it, even if it's just a little.
But the most important thing is to not go overboard - you won't need to study every last bit of material for hours so don't bother. Get a vague knowledge, study a bit more the parts you are unsure of, and start your revision early (and keep revision in mind when in term time - there's no point making notes in lectures that are useless when it comes to revision time, so make them clear and relevant!).
Also - you don't need to worry about work experience too much during term time unless you really need the money. There's no point slacking on your studying just to get the experience of serving customers in Aldi - save it for the summer holidays.