You need to increase the temp on your thermometer because that is only the temperature right next to the heater. you also need an air pump and air stone for better circulation. Also you are supposed to let the tank settle for afew days and let it run before you add new fish.
This is incorrect. You need to CYCLE the tank. Letting the tank run doesn't do anything except allow you to make sure the equipment all works and that there are no leaks. There is no benefit other than that to allowing the tank to run. You need to build a bacteria colony in your filter before the fish can safely enter. Some folks do a fish-ion cycle - but they watch the levels very closely to ensure that ammonia and nitrite remain as close to zero as possible. This involves a LOT of water changes and continually monitoring things. Others complete a fishless cycle. This involves adding ammonia to the tank and waiting for the ammonia and then the nitrite levels to drop to zero.
Seriously, read through the Nitrogen cycle link in the beginner's resource center thread.