Go shopping more often
Large purchases are only worthwhile if you really make a huge meal plan and have a large area available for stockpiling.
For a 1 to 4-person household it is sufficient to buy planned for a maximum of 1 week. Then the danger is not so big that you have to throw away a lot in the end. Some things can also be bought at short notice if you want to have them fresh or you know that you can only get them on certain days because you can only buy them at the market or they are only prepared on certain days.
So it's perfectly ok to make smaller purchases more often. It is important that you don't lose track of your stock and don't buy food that you don't need at the moment.