Um... Yes you need to be fully trained. They are not going to send a recruit on any courses aside the CIC one.
Further than that it might be hard depending on the role of the unit and so forth. If they are entirely vehicle based like a Sigs unit or even (gasp!) a logistics or MT section for example I'd think you have a better chance all round.
That aside if thats a cheif reason your considering joining - don't.
Im not expecting it next week, and for the note ive already signed up, its just a bonus more than anything. Seeing i don't have any money at the minute. Oh well, ill get it eventually not to worry huh?