Hy guys, i'm a 21 years old italian boy that is in doubt if going bald or not (sorry if my english is not perfect

)
i'm starting to thin on top and i have to take a decision.
I have some doubts because i have a very light complexion and i don't know if can i go bald...
on the contrary, at least i have medium brown hair (then not very dark) and i don't have a skinny body.
now i have some questions for you:
-Body hairs and hairs grow up at the same speed? because i've tried to shave my arm hairs in order to see how fast they grow up.
-If i shave my hairs every morning, within the evening i will have the same conditions of the morning or my hairs will be more evident?
all my concerns to go bald are about the shadow of hairs. at the moment i still have long hairs (about 40 cm) and i've just started Finasteride, but i know that i have to take a decision.
Sorry again for my english and thank to all for your answers!
p.s. is there any italian sly on this forum? can i know from them how is the bald life in Italy?