Make sure you're familiar with all parts of the Instant Pot. You have your base unit, which is where the cord gets attached for plugging into an outlet. The inner pot is placed into the base unit to hold the food you will be cooking. The lid lock goes on top to seal the Instant Pot shut.
If you're using a different pan to pressure cook in rather than the inner pot, use the trivet to securely place it in the base unit. Lastly, you may need foil to help keep certain foods moist or to help remove a pan without hurting yourself.
Image Source: POPSUGAR Photography / Hajar Larbah