I am seeing questions plus incorrect information about seeds.
Hybrid seeds and Open-pollinated seeds are opposites.
Hybrid seeds are a cross between related plants (such as two different tomatoes). This could happen naturally or by human intervention. This is not the same as GMO. If hybrid seeds are saved they may not grow at all. If they do, it is likely they will grow like one of the parents of they hybrid instead of like the plant the seed was collected from.
Open-pollinated seeds are the same as the plant it came from. If seeds are saved from an open-pollinated plant you will get the same thing as what the seeds came from. These are the types you want to plant if you want to save seeds and increase the chances of you getting what you expect. Heirloom are open-pollinated seeds that have been passed down for generations. So if your great grandfather grew a type of bean he really liked and wanted to grow it year after year and so saved the seeds and then passed them down to his children or grand children those would be heirloom seeds. Heirloom seeds are now collected by organizations that want to preserve some of these seeds so some seed companies sell these heirloom seeds. Many of these same companies also sell other open-pollinated seeds.
Seeds can last a few years if stored properly but germination rates are reduced over time. Seeds should be kept cool and dry. I store mine in zippered bags in a box in my basement. I live in a dry climate and my basement is not humid. Some store them in the refrigerator or freezer. I prefer not to do this unless it is temporary for seeds that need the cold before germinating. Refrigerators and freezers tend to pull moisture from food and could do the same to your seeds. Although seeds seem dry they do contain some moisture and it is not good to have them dried out more.
The best option is to purchase open-pollinated (heirloom or not) seeds of plants that you would eat, store them properly, grow them, and learn to save the seeds. Since this can be a learning process start with the easier ones such as peas and beans while continuing to purchase seeds while you learn and using seeds from previous years packets that were stored properly.
If you are saving seeds but not gardening those seeds will not provide much benefit. Gardening is a learning process. Mistakes will be made. Weather won’t cooperate. But each year you will get better and better at gardening.
There are several good companies that only sell open-pollinated seeds. I sell seeds from some of those brands at my store Basil & Rose where I only sell open-pollinated seeds.