Great to hear you're interested in getting into crit racing next year. As Alex says, come along to the intro and group skills sessions when you can. The Saturday 8am Regent's Park sessions are also good for honing your group riding skills, with the faster 7am crew offering a step up in pace (don't forget your ICC jersey, though!).
We also have other sessions that are useful for racing - I would highly recommend signing up for the Hillingdon race skills session https://forum.islington.cc/events/2483/ and the Thursday evening velopark skills sessions are also great https://forum.islington.cc/conversations/287922/ (I guess these are starting again in the new year).
Often the advice for those thinking of racing is to just give it a go. Don't worry too much about about whether you're fast enough - just finishing in the bunch on in your first race would be a significant achievement. You will find that after a couple of races you will be far more comfortable in the pack and can start thinking about strategy.
You likely to see plenty of other ICC jerseys at races around London. There's some general chat about upcoming races on the forum at https://forum.islington.cc/conversations/589/?offset=2125. Get involved!