a) The direction is found using the right hand rule. Imagine grasping the wire with right thumb in the direction of the current, the fingers will point in the direction of the field forming concentric circles about the center of the wire. Since the proton is above the wire the field direction will be out of the page in this case.
b) Force in a moving charge = qVxB where q is the charge in coulombs and VXB is the vector cross product of the velocity and field. Since the charge is positive the Force will be away from the wire in the plane of the page.
