They provide everything you need, as I’m sure would most assessment centres. However, I’d always suggest just taking a pen and paper with you in case (just to seem prepared).
As for a computer, I don’t think you’ll ever need this for an AC (unless explicitly told to bring one). For Macs, they don’t require one and give you one on the day. The reason being, you need access to their internal system so this cannot be pulled up on your laptop.
As for google, you are not allowed to search anything at all. To be honest, there will never be a need to. Everything you need is in the documents they provide, and I know it sounds a bit mysterious but once you open the documents you’ll see what I mean.
I definitely would not bother overthinking the AC. Easier said than done I know, but the minute I got there, you don’t even feel nervous anymore. The partners and associates, as well as the grad rec team are honestly so friendly and easygoing.
Personally, I was scared of the case analysis but I had so much fun in it. I remember just laughing with the partners and cracking jokes about the scenarios. I’m not saying crack jokes, but don’t stress about it because ultimately you’ll end up getting caught up in the nerves that it will just harm your performance overall.
Hope this helps, and wish you the best of luck.