If a reset of the Home screen layout did not restore the apps, then you may need to do a restore. After you did the reset, did you attempt to locate these apps via Spotlight? Check all of the folders you have, including any that may be titled Extras, or Utilities. One of those is created when the iOS setup is new to hold many of the Apple apps. That could be where they are located. Did you go into Settings>General>Restrictions, and see if you had a restriction for the Camera or other apps? If so, and there were no restrictions, then first try a restore from backup, and if necessary restore to factory. Camera and Safari are iOS native apps and cannot be deleted.