Hey sorry for the late reply, I blame jet lag

Great question!
This obviously depends on how you work / learn best!
It might be good to start with how teaching tends to work in a chemistry degree.
You will normally have lectures in each of your modules and these are usually 1 hour long.
It depends on your lecturer, but they often post copies of the notes (maybe with some blank spaces to fill things in), a few days before the scheduled lecture and you can either get those up on a device or print them.
(I like to print mine and then scribble notes on them but I've seen all sorts done!).
Other teaching methods involve workshops / Q&A, which is more you go to the session, get given some questions to attempt then and then if you're stuck you ask for help from the teaching member of staff present. The Q&A is usually a bit more audience-focussed, so you can ask anything you were unsure about or to go over specific questions/past paper content.
In terms of comparing to 6th form, kinda depends how you learn!
I find it difficult to memorise things, so what I did was after the lecture, I'd have these scribbled notes and I would write the entire set of notes in an A5 notebook. I did this for each module. When it came to exam time, I condensed these notes into flash cards to test myself!
E.g. if you're a visual learner you might be better doing more diagrams/mind maps.
The lectures are also sometimes recorded so you can actually watch them again - can be super helpful
Past papers are usually available. Note that if the module is new, there is often only 1 past paper (the sample past paper, to see what an exam would look like).
Don't think it depends on the professor in terms of past papers, may depend on Uni policy e.g. I went to Southampton and I believe they had a strict policy in their being at least one past/sample paper present
Hope this helps + sorry for the delay in getting back to you
@BooksAndTea789