Hi there!
Though I’m pretty new, I’m proud to say I completed a fish in cycle that is finally done after close to 2 months. Happy to share my small thoughts, again, I emphasize, I’m still new.
At least for me. The ammonia will take a while, just feed them lightly. Thing is once it comes, it’s a huge steep curve, so you gotta keep up with the water changes, to at least have it below 0.2ppm. (I remembered a week where I had to do a WC each 3-4 days). Then of course, the nitrite spike.
Is your tank planted? Cause that lowers the ammonia a little (which is also a good thing).
I had Seachem Prime by my side and it’s a good protection for the fishes which I dose every 1-2 days. I attempted to speed it up a little with Seachem stability as well.
Also since the fishes are new, are they eating well/regularly? Otherwise they probably have not started to really produce waste yet.