Agree with Andy you should try to get some O2 admin training, and as others have said do some rescue training as soon as you are able.
From my experience with Fundamentals, I was very lucky and hooked up with two top blokes just before DIR-F and had an idea of what to expect. I've yet to meet a GUE trained diver that won't go out of their way to help people out, so search one out and go diving
I wouldn't waste your time honing skills - in fact Mike Kane, the GUE instructor that took my Fundies class, said he prefers people NOT to do that because invariably you are doing it wrong and he then has to make you "unlearn what you have learned" (little Yoda quote there, sorry
).
My advice would be do the Rescue stuff asap, configure your gear DIR and get some dives in with GUE divers, just working on getting flat trim and good buoyancy. When you turn up to the class you will learn (correctly) the relevant skills, if you don't get a full pass so what?? The cert card means nothing anyway... you will get a provisional (unless you are dangerous/a complete muppet
) and you can then practice the correctly learned skills in your own time.
Hope this helps!
Fraser.