Adventist Youth Honors Answer Book/Nature/Seeds/Seed collection
Seeds are all around you. You can find them in many fruits, such as apples, oranges, pears, grapefruit, tangerines, strawberries, lemons. They are also present in many vegetables, such as cucumber, squash, pumpkin, corn (use popcorn for your collection), and beans of all varieties. Take a stroll through the produce section of a grocery store and buy some of these foods. It is especially fun to try new and unusual fruits and vegetables.
Flowers also make seeds, so you can collect seeds from flowers that you already may have growing in your flower bed or someone else's flower beds (with their permission).
You can also collect various seeds in the wild, including grass seeds, milkweed, acorns (and other nuts), clover, goldenrod, etc.
Once you have exhausted these sources, go to the seed section of a store or a nursery. This should be reserved as a last resort.