Yes, of course, you can do that. The same as eyeglasses, contact lenses are more than a fashion accessories, they can provide you vision aids no matter you have problem to see far or see near. Even if you have vision problems for seeing both near and far, you can get bifocal contact lenses or varifocal contact lenses to help you. Just remember taking your prescription when you contact lenses. Getting prescription contact lenses surely provide your dad vision aids.
Of course you can, but I think you may only need them when you get older. Yeah, just like your father. And I strongly suggest you to get your dad bifocal contacts, which can be good for his eyes, for both distance vision and nearby vision. To be honest, you had better tell your father not to wear contacts. As your father is getting older and older, some of his eye functions also decrease with his age. If he wears contacts for a long time, it will be easy for him to get his eyes to be infected. Anyway, this totally depends on you.