The Calibrachoa llave, also known as "Million Bells," is a miniature version of the petunia. The Calibrachoa can either be an annual plant or a perennial, depending on which U.S. Department of Agriculture plant hardiness zone you inhabit. In the cooler zones, 3 through 8, the plant is an annual, while in the warmer ones, 9 through 11, the Calibrachoa is a perennial. It is difficult to obtain seeds from the Calibrachoa, because it does not produce many, so it is mostly sold in the form of live plants that are propagated from cuttings taken off of another plant.
Wait until your current Calibrachoa plant flowers. Once the flowers have bloomed and dried up, snip them off at the base with a pair of garden shears. Place the flowers in a small box and gently shake them. Any seeds that they have produced will fall off onto the bottom of the box. Discard the dried flowers.
Check with a friend or neighbour who has a Calibrachoa plant if you do not currently have one in your yard. Once their plant has bloomed, ask if you can have any seeds that their plant has produced.
Go to a local home and garden centre. Check to see if they have any Calibrachoa seeds for sale. Although the plant is mostly sold as a grown seedling, retailers may also have seeds available.
Look online at plant and seed sellers. They also sell Calibrachoa plants as seedlings but may have seeds available for purchase.