Ask the guardroom about parking. They will advise you. If parking is verboten, stop trying to be clever and 'beat the system'. No one likes a smart arse, especially if they aren't even out of basic yet.
Or keep your bike at home. Use the rail warrants to get to and from camp until you join your parent unit. Which by then you will be out on the pish with the lads most of the time, too ball-bagged to go out on it or both.
As ive seen in the Joining Instructions on the website Recruits are not allowed to take personal vehicles to Phase 1 so unlikely youll be able to park on camp so if you really need to take your bike you might be able to park nearby but id just use the train travel warrants