Go through your cupboards and fridge to find all of your fats and oils. Industrial seed oils grow rancid rather quickly and can be converted to a trans fat when heated, so all the more reason to give them a toss now.
Take a look at the fats to avoid - they need to go - then head to the store for the fats to embrace.
Butter (especially grass-fed butter like Kerrygold) is what I use 99% of the time to cook with. I also keep avocado oil on hand to grease my air fryer, whip up some mayo or salad dressing and even use for frying. I use coconut oil for baking, frying, greasing, moisturizing and for oil pulling (whiter teeth without the chemicals).