The product  of H2SO4 + NaOH  is Na2SO4  and H2O
Explanation\
Base  react with an acid  to form  a salt  and waterNaOH  is  a base  while H2SO4  is  an acid therefore, NaOH  react with H2SO4 to form Na2SO4(salt)  and H2O  according to below reaction
     2NaOH  +H2SO4  → Na2SO4 +2H2O