If your Witcher 3 console commands do not work then fear not! Often there is a very simple explanation that can help you. Remember to always save your game before you start using these codes as bugs/glitches are known to happen.
How to activate the Console
Download and install the Debug Console from Nexusmods. Use the ~ key to bring up the console ingame. Copy/paste the commands (to prevent typos).
Check the command for errors
If the command has a capital letter, you must type it. Check the brackets, spaces, dashes and quotation marks. The command will not work unless it is input exactly as shown.
HoS does not activate before you complete the prologue
It seems you cant spawn any HoS items before you reach Velen. This is probably because it only loads once you complete the prologue (White Orchard). This is also true on NG+ and is why you cannot start NG+ and instantly load HoS items.
Spawning items does not give achievements
If you spawn Gwent cards hoping to get the achievements then you will find it does not work. You must go through and play the matches/purchase everything required before you can unlock the achievement. In short, you have to still go through all the work of collecting the cards manually.
Hope this helps
If you have any more questions regarding console commands etc then please post below.