Moving this to "sticky", because it's an important topic for buying seeds for next year, and stocks of some popular seeds will run out quickly. Also, we are expecting significant food price inflation next year.
I suggest keeping it simple, and growing core staple crops (not celery...) that you know you can use in large amounts, and that you know you can grow. Avoid tricky not to mention low-calorie, low-yield crops. I should talk--I'm growing cauliflower. But it's easy to grow in MY climate (harder in most others--it's a fussy crop), and I'm just growing a few plants.