When you will register. Probably you will start as academy student. And you will Get 60 health points. That means Whit doing missions and gaining experiance whit that your level will grow. and by that You will gain +5 whit your standart health..
Ofcurse if you are higer rank your Health points will be more and you will be stronger.
So Do your missions gain experiance and You will raise as an great Shinobi.
((Drake if theres mistakes You can edit them))