Help with my mod

Hello, I need help with something, i'm making a mod, that is based on a game, so i made a dimension and thats tha place where is going to be the mod, so i want to made the inventory of the game but i don't know how can i replace the normal inventory with the modded inventory, and i want to do that when you enter in the dimension, the game put the modded inventory replacing the normal inventory and when you are in the normal dimension (overworld) the inventory is the normal one  (sorry my english is bad :c)