Johnny's Seeds has these tips (they have lots of good gardening advice).
"Transplant - Dill can be started indoors in containers or cell trays. Sow 3-5 seeds per cell. Transplant out using 2-4" spacing in rows at least 4" apart."
I also saw that "Dill does not transplant easily," from the #UMN Cooperative Extension website. So best to plant them in bigger pots to begin with.
https://www.johnnyseeds.com/growers-library/herbs/dill/dill-key-growing-information.html