Well done!
I did the AC last year, so the format may have changed from this, but I can give tips from my experience
The AC consisted of:
1. Proofreading exercise - we were each given a legal document and had to amend any errors, grammatical mistakes and so on.
2. Letter to client - we were given a case study about the sale of land/a property and needed to highlight to the client the key issues in a letter. This did not require much legal knowledge as the issues are set out very clearly in the case study, and i think you are judged more on ability to summarise / write letters as opposed to application of law. (For context I had never studied law and found it to be ok)
3. Filling in a contract - I found this to be harder having not studied law
4. Client interview - we were told a few days in advance we were doing an initial interview with a client, who had a clinical negligence issue. We then had 15 mins to speak with the hypothetical client and ask questions and gauge the key facts of the case etc
5. Interview with partner/associate - mostly competency based Qs but a few Qs about the firm eg what is a recent case that Penningtons has worked on that interests you
hope that helps!