Ok I'm so confused about balancing chemical reactions

What is the balanced chemical equations for these reactants:
AgNO3(aq)+CaCl2(aq)--->AgCl(s)+Ca(NO3)2(aq)
Mg(s)+N2(g)--->Mg3N2(s)
CuCO3( )--->CuO(s)+CO2(g)
Zn(s)+2HCl(aq)--->2ZnCl(aq)+H2(g)

And also what is the word equations for each of them?

Please help! Due tomorrow!

Here is a link to an excellent explanation of how to balance chemical reactions by Unknown008