It all just depends on what kind of relationship you want with the horse, if you want more ground time or ground relationship with the horse then full lease because you get ground and ride time. If you want just ride time then half.
Hope This Helps!
Definitely half if you are a beginner.
Half lease to try the horse out and if you like him go to full lease
Full. More time on the horse
Do half lease and if you are really considering it then later do full lease or buy
Do half first and see how it goes! If it goes well and your parents are ready for it too then do full!