Toyota parts need some repairs..

One of the important part of a vehicle were the wheels and tires. They need to be aligned to have the perfect driving function. But if I have heard something from it or have some difficulties in turning to directions, anything to do with the ball joints? Can it be checked first or if ever some problems occur, do we have to replace it at that time? And how long it can handle in it's place? Like the Toyota Rod End, do we have to change them both or can we have it replace one at a time? and what do I have to prioritize first?