Question

To which group and period should hydrogen be assigned?

Answer 1

It is generally grouped in 1st group of periodic table.... 
and to 1st period too..but it is debate topic why it is placed there.... 

Answer 2

Look bro,

Little higher grade answer -

H2 is a non metal and should be placed above in the periodic table because it has ns¹ electron configuration like the alkali metals.

Well, I'd like to ask you to look carefully in the periodic table, Hydrogen is kept separately above Group 1.

thanks.

all the best!