do it now! Law changing again on license, so if you go for the restricted test you will be stuck at 33bhp for ever, unless you go back and take your test on a bigger bike.
Good grief, as CB used to say!
CBT is one day, designed to make you shudder at the thought of being on the open road. Choose a school with private training area big enough to get used to bikes with engines, and have fun. Most good CBT places can provide clothing and safety gear, so you don't need to invest until you want to commit to joining the happy few roaming around without worrying about traffic queues.