Welcome to R2R! Nitrites will drop to or near zero; Nitrates will climb like crazy. Big water changes to lower the nitrates down to 20ish ppm. Some continue to either dose ammonia, ghost feed with a bit of flake food. Usually the first sign are a few pink or red or green spots scattered about on the rocks. Then you usually get some bright, almost lime green algae on the rocks. After that the "new tank uglies" which is various forms of algae cycles requiring some elbow grease: toothbrush, turn up powerheads while toothbrushing, wait a bit and then change filter socks - repeat as necessary along with regular water changes.