There are many buzzwords for reducing your waste. My favourite term is low waste. You might have heard of zero waste but I like to avoid the word zero as a perfect "zero" waste goal is impossible. The goal should be to reduce as much as possible within a realistic timeframe.
The best way to start your low waste journey is to look in your own garbage and see what you have. This is refered to as a waste audit. You can start by focusing on items in there that you think would be or find items that you see most frequently that could if you eliminate them from your shopping list.
Remember to take it slow to not get overwhelmed!