To activate in game cheats, you need to hit the TAB key to bring down the console, and then type CheatsPlease. After this, you can then type in any of the following cheats:
A handy trick is to bind your keys to certain cheats. To do this, you need to edit the User.ini file. Simply use a text editor (Notepad or Wordpad) and bind a key to CheatsPlease and another to God (or any other cheatcode). For example, to bind CheatsPlease to key X and God mode to key G, just have this line in your User.ini:
When you play the game, you can then hit X to activate cheat mode, and then hit G to activate God Mode.
To spawn items, you first have to activate the cheats, as above, and then the TAB key to access the console. Use the Summon [ITEM NAME] cheat to spawn the items as per the below guide: