All plants grow seeds. Some do it only very rarely. Seeds are a mechanism for evolution - when cloning reproduces identical plants, plants grown from seeds are a combination of the genotypes of the mother and father. Every combination is slightly different and this is the base for breeding new plant varieties.
So every seed you plant will grow into a genetically unique organism.
As the first step you need to get your plant flowering. This should not be so hard when using the Click and Grow system. It only takes patience. The French marigold, Mini tomato and Chili pepper are the easiest to start with.
The second step is not to pinch off all wilted flowers. Also keep in mind, that producing seeds exhausts the plant. If you want the best quality seeds, it is advisable to leave only a few "production" blossoms.
Wait and observe - the flower will turn into a seedpod. It may take a long time for the seeds to ripen. Ripe French marigold seeds are 1 cm long and almost black. They can be easily removed from the flower. Shake the flower gently and the seeds will fall on your hand.
Take the seeds and plant them in your garden.