The worms might have been rhabdocoela flatworms as well. They are pretty common in tanks, more so than planaria.
You shouldn't need to add any conditioners to a cycling tank, but you could try a product that could help cycle it... (i.e. bacteria) If there is an issue with ammonia, nitrites or nitrates, it's fine to add Prime to the tank, but it would probably be best to use after doing a water change to reduce those first... in which case, you would be adding it to the water going into the tank anyway. Just make sure not to over-dose it... shrimp don't like that either!
You shouldn't have shrimp in an uncycled tank.
Being that you live in Florida, your water might be too soft for the shrimp to live in long term and they might perish due to lack of minerals. It would be recommended to get a liquid GH and KH test kit along with a TDS meter (and calibration solution).