The inventory is the space around the player body where you can wear your clothes, place the things you want to keep close, and additional items. There are different ideas on the topic so the inventory might not be in the basic game itself, it might just be added by different mods:
Minecrafts inventory allows you to carry huge amounts of tons of materials, and all together at maximum 36 different types. Minecraft mods allow to add backpacks which can carry huge amounts again. However as clothes there is only armor.
Clothes are nice features when you want to protect you from extreme temperatures, icy winds, rain, and venomous plants. So the best idea for an inventory cloth system would be to add a warmth protection value and protection values for physical hits at this parts. Also there need to be stackable slots for all regions of the body: feet, legs, hips, main body, arms, maybe the neck and the head.
Do you know those indian carriers? Well I might not allow you to carry soooo much, or might give you that feature as reward for hard training. Normally you should be able to carry 6-9 hands full + when enoughly trained on your head. Also a wheelbarrow or vehicles would be a nice help.