It depends if your front jacks are electric or hydraulic.
If you know your pad is level, and you are just questioning the one jack coming down before the other starting to move, or one seems to be behind the other. That is OK and normal in an hydraulic system, once they both get back pressure they will equalize and lift the unit together equally.
If the jacks are electric, they both should come down at the same time, if they don't you have a gear problem on the lagging jack.
If you are still in doubt about level, put a 4 or 6 foot level in the 5th wheel several places and see what it is. As the saying goes, the proof is in the pudding. LOL
Help this helps and God bless,
Mike