The thumb, the first and the second fingers on the left hand are held so that they are at right angles to each other.
If the first finger points in the direction of the magnetic field and the second finger the direction of the current in the wire, then the thumb will point in the direction of the force on the conductor.
Alternatively, imagine you are running though a forest in the direction of the current. The magnetic field points in the direction of the trees. You will experience a force pushing you to the right.