Do you get the same amount of Ability points at character creation? Or does it reroll if I cancel and try it again? Or doe different classes get more or less ability points.

All classes get the same amount of points every time. Some races get bonusses or penalties in certain fields as described in your manual.

Thanks

Adding to that^ Although all classes get same amount of points to distribute, since half-orcs get two penalties and one bonus, then, point buy system aside, they generally get a total that is 2 less than others.