You can use any calendar app you like - there are plenty in the Play Store, including Google's own.
By "default", what do you mean? If you have an icon, replace it with the calendar app of your choice. If something is starting the Samsung calendar by default, generally going into the Applications menu, selecting the app and then "clear defaults" fixes this.
I don't have this phone, so don't know whether there are some quirks, but the above should work for android in general.