Weapons

You can use any starting weapon normally, which replaces your natural weapon attack.

By spending gold equal to the gold cost of a melee weapon, you can have your natural weapons modified to resemble those weapons.

By spending a Short Rest with a magic melee weapon and attuning to it if necessary, you can learn to channel it's powers into your natural weapons, though, by doing so, they also end up inheriting the same damage dice and other properties, almost as if it works exactly the same as actually wielding the thing.

Ranged weapons, on the other hand, are a bit more difficult. You can get a ranged weapon which works with your physique custom built by paying twice the GP price usually required for that item.