Hi, I'm taking mine in 2 days time. I'm currently in the last year of 6th form and also intend to start in July (at a push) but ideally October.
I purchased the Symbiotics cadet pack (£48 using the CAE link) and have been working on it daily and really glad I purchased it. it's exactly what you'll be using in your stage 2 so it alleviates some of the stress of not knowing what to do on the day, and many have said the questions are fairly similar.
It identifies areas of weakness so you can work on those items, mine was mainly around the physics questions as it's not something I've done for a few years and all to be fair is GCSE level, noting harder.
Personally the FAST test is the one that will help you the most in addition to the others, if I had gone straight into a test without the 5 trial ones it would have been evil
Also be looking to share a house near to CAE if anyone is in the same boat
Josh