Suggestion:

Pull the valve cover + timing cover, and do the belt inspection described in the manual. Can't mess up much that way. Rotate the crank a few times, make sure you can find the timing marks, adjust the tensioner, loosen and retorque the crank pulley bolt etc. Then reassemble without taking the timing belt or pump off the car.

If you have trouble, let someone else replace the belt and pump. If all goes well, do the belt another another day.