You can access it by opening the game menu and navigating to the tab Inventory.
Highlighting an item in the inventory will tell you what it is used for and where you can find it. Homeopathics and some Throwables can be crafted by the player, using the Components in the inventory.
Your weapons, outfits, consumables and utility items are not available in the inventory; they can be accessed through different menus.
If you have any questions, feel free to contact us!