Getting rid of the widgets/icons is easy. Getting rid of the app entirely.. not so much
To remove the widget or icon, long-press the item, after a brief period you'll see some options appear at the top of the screen, one is delete (or remove). Drag the item there and it will disappear off your home screen.
To remove the app entirely is a whole other story. If it was on the phone when you took it out of the box, it's there for good unless you do some advanced tweaking. The good news is that you can DISABLE the app. This doesn't remove it and free up the space but it gets it out of sight. Open settings, locate the Applications section (Samsung mucks with the menu so I'm not sure where they put it), locate the app you want to disable and tap it. On the resulting screen will be several buttons, one should be labeled "disable", if the app has been updated since the version that was pre-installed it will actually say "uninstall updates", if you tap that it will verify you wanted to do that and then the button should change to "disable". Once you have the disable button, tap it and it will disappear from the app drawer and won't load or even update if there's an update. If you decide later that you want the apps to work again, go to the applications section, locate the "disabled apps" section, locate the app you want to re-enable and do it.