I like this one boy, and I would like to know how would it be possible for me to let him know, so that we could marry each other someday?

According to the Shari'ah, it is prohibited to have any contact with a Ghayr
Mahram (not prohibited in marriage) males before marrying the person.

Ghayr Mahram males and females must observe Hijaab with one another. It is
the non-observance of Hijaab that leads to many evils, among them, one is,
for example, liking the boy. You should make an effort to keep your distance
from the boy and purify your heart and mind from that thought as that may
generate many more evil thoughts, especially, in today's times of evil and
corruption.

and Allah Ta'ala Knows Best

Mufti Ebrahim Desai