Every tank is different. If you stock heavily with fast growing plants, especially hungry stem plants and floaters like water lettuce and hornwort, you shouldn't have any ongoing ammonia issues.
People dirt tanks all the time, wait a few days and add fish. That said, you want to monitor your parameters for some days first. I just set one up and didn't test anything before adding fish, but you get a feel for these things over time. With all those floaters eating and growing, and with the soil I used, there was no way I was worried about ammonia. Just take it a step at a time.
I sifted my dirt through some 1/4" hardware cloth to remove any larger particles, and in my case rocks. I just used topsoil from the property where I live mixed with some Turface and some red clay balls.