Movie 1
In this movie there are two families competing each other to prove which one is better. I think the two dads were friends or something. Both the families have come to their holiday home.

Movie 2
In this movie there's a girl whose diary gets accidentally published, and she becomes famous. Then late, everyone finds out , etc.

Thank you very much! :)

Movie 1: Would it be "Deck the Halls" with Danny Devito as Buddy Hall, co-starring Matthew Broderick as Steve Finch?

Movie 2: "Read It and Weep" (previously titled How My Private, Personal Journal Became a Bestseller)