Lift the front of the truck. Spin each wheel and feel for smoothness vs rough. Also grab the wheel at 12 and 6 and wiggle. If there’s any play, check to see if it’s the bearing or the ball joints. Wiggling the wheel while grabbing it at 3 and 9 will help distinguish the difference as well. There should be no perceptible play in the bearings. Very little, almost no perceptible play in the ball joints if any. Everything should be tight and smooth.
Yup every oil change.Grease them regularly and they last almost forever.
Yup every oil change.