What is the pressure of a 12g sample of N2 in a 10.0l container at 25°c?

The combined gas law is completely defined by one equation.

PV = NRT

where

P = pressure
V = volume
N = quantity of gas
R = a constant depending on what units you want to use
T = absolute temperature

Next you go to google.com and type "gas constant". That leads you to
en.wikipedia.org/wiki/Gas_constant

You want a constant to use grams, liters, and centigrade. You have to convert your grams to moles. I am going to let you study the page and figure that out because that is what you need to learn.

BTW you should remember that L looks very much like 1 and you should type carefully to avoid that confusion, even spelling "liters" if that's what it takes. You can not stand spelling mistrakes in chemistry.