Do not grow heirlooms (open pollinated) in close proximity to other same family members or they may cross pollinate.
nor in proximity to standard hybrids (same reason, pollination "crossover")
For Example:
Bell peppers, tomatoes, potatoes, ground cherries, and eggplant are of the Solanaceae family known for fruits and vegetable production.
also,
Broccoli, Brussel sprouts, kale, cabbage, cauliflower, and bok choy are of the Cruciferous family (known for their leafy greens and buds)
Anyway, it is all a learning experience, and
you will learn more from failures than you will from successes.
Learn now, before you have to rely on your own productivity.
Gardening productivity and seed saving are also bartering skills.