>>321486981
>do I still need one of those inventory systems
you don't, they're just there to make it a bit easier to manage lots of them I imagine
items work the same way. You add it to your project, position it on your avatar the way you want (and constrain it to whichever body parts you want) and after that you disable it (ie press the checkmark in top right when selecting that game object in unity).
Then you start recording an animation and enable that item, create a new expressions menu entry and make it of type Toggle where you play that animation
https://www.youtube.com/watch?v=ROp4GHBj1N8
>>321487046
good luck with it anon, and most important: have fun