lets' think about this. in a double replacement reaction, the 2 reactants must be aqueous and one of the products must be a precipitate. here, your two reactants are both nitrates. all nitrates are soluble. there is no double replacement reaction because you have 2 nitrates and switching cations would just create the same reactants. they are 2 aqueous substances that will not form a solid precipitate
Solutions of these two salts would not react as no new compounds can be formed.
I think you meant NaCl and AgNO3
If you mix these two solutions you will get a precipitate of Silver Chloride
NaCl (aq) + AgNO3 (aq) ===> AgCl (s) + NaNO3 (aq)