Take it back to the alignment shop and they should re-do it for free. If you paid for it, your steering wheel should be straight.

The best hand position for straight ahead steering is to think of the steering wheel as a clock. The best position would be to have the hands on the 3 and the 9, which is what people are taught when learning how to drive.

When you have the front end aligned the mechanic should align the steering wheel also. This is so the steering wheel is positioned straight when you're driving straight down the road.

Under steering is when a car is in a turn and it continue straight or pushes the front end through the turn while the steering wheel is turned.

A good and accurate front-end alignment.

All the parts of the steering and suspension "point straight down the road" will establish the steering wheel to do the same.

Anything out of alignment will pull/push the wheel(s) in that direction.