The main menu tells you how many things how many things are in your inventory (1) and allows you to call up a list of them (2). These are all game items that are with you (imagine them being in your pocket), and you can interact with them (if the game allows) at any point..
Tapping on “Inventory” calls up a list of the things in your inventory (1)
Tapping on each thing calls up options of how you can interact with each thing (if you can). How you interact (what you do in the game) appears on the button at the bottom of the screen (3)
You may have multiple choices of what to do (3)
Your inventory is often the “go-to” place if you are stuck. Examine each item closely. In this instance, if the bikini-clad starlet in your given location won’t talk to you, put on the World’s Sexiest Hat to make yourself irresistible to bikini-clad starlets.
If there is a phone or radio in your inventory use them to call someone.
Sometimes things in the “You See” option can be moved to the inventory. Some things have to be picked up or put down.