Can you modify weapons? (Far Cry 5)

Can.

The game has the ability to deliver:
2 muffler (square and round). The difference between them is no other than form.
A variety of sights, ranging from holographic, ending with the optics.
To set the zoomed clip.
To change the skin of weapons.

Also in the store you can buy a variety of ammunition (normal, armor-piercing).
In a game of very few modifiers on weapons. And the weapons as such - a little.

yeah,I already figured out,this is done through the store

Very stupid questions)

RTYWD
Yes, I know you just have played and I have no

Do not tell me, at what stage can you start doing this?